1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * Copyright (C) 2002 Richard Henderson
4 * Copyright (C) 2001 Rusty Russell, 2002, 2010 Rusty Russell IBM.
7 #define INCLUDE_VERMAGIC
9 #include <linux/export.h>
10 #include <linux/extable.h>
11 #include <linux/moduleloader.h>
12 #include <linux/module_signature.h>
13 #include <linux/trace_events.h>
14 #include <linux/init.h>
15 #include <linux/kallsyms.h>
16 #include <linux/file.h>
18 #include <linux/sysfs.h>
19 #include <linux/kernel.h>
20 #include <linux/kernel_read_file.h>
21 #include <linux/slab.h>
22 #include <linux/vmalloc.h>
23 #include <linux/elf.h>
24 #include <linux/proc_fs.h>
25 #include <linux/security.h>
26 #include <linux/seq_file.h>
27 #include <linux/syscalls.h>
28 #include <linux/fcntl.h>
29 #include <linux/rcupdate.h>
30 #include <linux/capability.h>
31 #include <linux/cpu.h>
32 #include <linux/moduleparam.h>
33 #include <linux/errno.h>
34 #include <linux/err.h>
35 #include <linux/vermagic.h>
36 #include <linux/notifier.h>
37 #include <linux/sched.h>
38 #include <linux/device.h>
39 #include <linux/string.h>
40 #include <linux/mutex.h>
41 #include <linux/rculist.h>
42 #include <linux/uaccess.h>
43 #include <asm/cacheflush.h>
44 #include <linux/set_memory.h>
45 #include <asm/mmu_context.h>
46 #include <linux/license.h>
47 #include <asm/sections.h>
48 #include <linux/tracepoint.h>
49 #include <linux/ftrace.h>
50 #include <linux/livepatch.h>
51 #include <linux/async.h>
52 #include <linux/percpu.h>
53 #include <linux/kmemleak.h>
54 #include <linux/jump_label.h>
55 #include <linux/pfn.h>
56 #include <linux/bsearch.h>
57 #include <linux/dynamic_debug.h>
58 #include <linux/audit.h>
59 #include <uapi/linux/module.h>
60 #include "module-internal.h"
62 #define CREATE_TRACE_POINTS
63 #include <trace/events/module.h>
65 #ifndef ARCH_SHF_SMALL
66 #define ARCH_SHF_SMALL 0
70 * Modules' sections will be aligned on page boundaries
71 * to ensure complete separation of code and data, but
72 * only when CONFIG_ARCH_HAS_STRICT_MODULE_RWX=y
74 #ifdef CONFIG_ARCH_HAS_STRICT_MODULE_RWX
75 # define debug_align(X) ALIGN(X, PAGE_SIZE)
77 # define debug_align(X) (X)
80 /* If this is set, the section belongs in the init part of the module */
81 #define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))
85 * 1) List of modules (also safely readable with preempt_disable),
86 * 2) module_use links,
87 * 3) module_addr_min/module_addr_max.
88 * (delete and add uses RCU list operations).
90 DEFINE_MUTEX(module_mutex
);
91 EXPORT_SYMBOL_GPL(module_mutex
);
92 static LIST_HEAD(modules
);
94 /* Work queue for freeing init sections in success case */
95 static void do_free_init(struct work_struct
*w
);
96 static DECLARE_WORK(init_free_wq
, do_free_init
);
97 static LLIST_HEAD(init_free_list
);
99 #ifdef CONFIG_MODULES_TREE_LOOKUP
102 * Use a latched RB-tree for __module_address(); this allows us to use
103 * RCU-sched lookups of the address from any context.
105 * This is conditional on PERF_EVENTS || TRACING because those can really hit
106 * __module_address() hard by doing a lot of stack unwinding; potentially from
110 static __always_inline
unsigned long __mod_tree_val(struct latch_tree_node
*n
)
112 struct module_layout
*layout
= container_of(n
, struct module_layout
, mtn
.node
);
114 return (unsigned long)layout
->base
;
117 static __always_inline
unsigned long __mod_tree_size(struct latch_tree_node
*n
)
119 struct module_layout
*layout
= container_of(n
, struct module_layout
, mtn
.node
);
121 return (unsigned long)layout
->size
;
124 static __always_inline
bool
125 mod_tree_less(struct latch_tree_node
*a
, struct latch_tree_node
*b
)
127 return __mod_tree_val(a
) < __mod_tree_val(b
);
130 static __always_inline
int
131 mod_tree_comp(void *key
, struct latch_tree_node
*n
)
133 unsigned long val
= (unsigned long)key
;
134 unsigned long start
, end
;
136 start
= __mod_tree_val(n
);
140 end
= start
+ __mod_tree_size(n
);
147 static const struct latch_tree_ops mod_tree_ops
= {
148 .less
= mod_tree_less
,
149 .comp
= mod_tree_comp
,
152 static struct mod_tree_root
{
153 struct latch_tree_root root
;
154 unsigned long addr_min
;
155 unsigned long addr_max
;
156 } mod_tree __cacheline_aligned
= {
160 #define module_addr_min mod_tree.addr_min
161 #define module_addr_max mod_tree.addr_max
163 static noinline
void __mod_tree_insert(struct mod_tree_node
*node
)
165 latch_tree_insert(&node
->node
, &mod_tree
.root
, &mod_tree_ops
);
168 static void __mod_tree_remove(struct mod_tree_node
*node
)
170 latch_tree_erase(&node
->node
, &mod_tree
.root
, &mod_tree_ops
);
174 * These modifications: insert, remove_init and remove; are serialized by the
177 static void mod_tree_insert(struct module
*mod
)
179 mod
->core_layout
.mtn
.mod
= mod
;
180 mod
->init_layout
.mtn
.mod
= mod
;
182 __mod_tree_insert(&mod
->core_layout
.mtn
);
183 if (mod
->init_layout
.size
)
184 __mod_tree_insert(&mod
->init_layout
.mtn
);
187 static void mod_tree_remove_init(struct module
*mod
)
189 if (mod
->init_layout
.size
)
190 __mod_tree_remove(&mod
->init_layout
.mtn
);
193 static void mod_tree_remove(struct module
*mod
)
195 __mod_tree_remove(&mod
->core_layout
.mtn
);
196 mod_tree_remove_init(mod
);
199 static struct module
*mod_find(unsigned long addr
)
201 struct latch_tree_node
*ltn
;
203 ltn
= latch_tree_find((void *)addr
, &mod_tree
.root
, &mod_tree_ops
);
207 return container_of(ltn
, struct mod_tree_node
, node
)->mod
;
210 #else /* MODULES_TREE_LOOKUP */
212 static unsigned long module_addr_min
= -1UL, module_addr_max
= 0;
214 static void mod_tree_insert(struct module
*mod
) { }
215 static void mod_tree_remove_init(struct module
*mod
) { }
216 static void mod_tree_remove(struct module
*mod
) { }
218 static struct module
*mod_find(unsigned long addr
)
222 list_for_each_entry_rcu(mod
, &modules
, list
,
223 lockdep_is_held(&module_mutex
)) {
224 if (within_module(addr
, mod
))
231 #endif /* MODULES_TREE_LOOKUP */
234 * Bounds of module text, for speeding up __module_address.
235 * Protected by module_mutex.
237 static void __mod_update_bounds(void *base
, unsigned int size
)
239 unsigned long min
= (unsigned long)base
;
240 unsigned long max
= min
+ size
;
242 if (min
< module_addr_min
)
243 module_addr_min
= min
;
244 if (max
> module_addr_max
)
245 module_addr_max
= max
;
248 static void mod_update_bounds(struct module
*mod
)
250 __mod_update_bounds(mod
->core_layout
.base
, mod
->core_layout
.size
);
251 if (mod
->init_layout
.size
)
252 __mod_update_bounds(mod
->init_layout
.base
, mod
->init_layout
.size
);
255 #ifdef CONFIG_KGDB_KDB
256 struct list_head
*kdb_modules
= &modules
; /* kdb needs the list of modules */
257 #endif /* CONFIG_KGDB_KDB */
259 static void module_assert_mutex(void)
261 lockdep_assert_held(&module_mutex
);
264 static void module_assert_mutex_or_preempt(void)
266 #ifdef CONFIG_LOCKDEP
267 if (unlikely(!debug_locks
))
270 WARN_ON_ONCE(!rcu_read_lock_sched_held() &&
271 !lockdep_is_held(&module_mutex
));
275 static bool sig_enforce
= IS_ENABLED(CONFIG_MODULE_SIG_FORCE
);
276 module_param(sig_enforce
, bool_enable_only
, 0644);
279 * Export sig_enforce kernel cmdline parameter to allow other subsystems rely
280 * on that instead of directly to CONFIG_MODULE_SIG_FORCE config.
282 bool is_module_sig_enforced(void)
286 EXPORT_SYMBOL(is_module_sig_enforced
);
288 void set_module_sig_enforced(void)
293 /* Block module loading/unloading? */
294 int modules_disabled
= 0;
295 core_param(nomodule
, modules_disabled
, bint
, 0);
297 /* Waiting for a module to finish initializing? */
298 static DECLARE_WAIT_QUEUE_HEAD(module_wq
);
300 static BLOCKING_NOTIFIER_HEAD(module_notify_list
);
302 int register_module_notifier(struct notifier_block
*nb
)
304 return blocking_notifier_chain_register(&module_notify_list
, nb
);
306 EXPORT_SYMBOL(register_module_notifier
);
308 int unregister_module_notifier(struct notifier_block
*nb
)
310 return blocking_notifier_chain_unregister(&module_notify_list
, nb
);
312 EXPORT_SYMBOL(unregister_module_notifier
);
315 * We require a truly strong try_module_get(): 0 means success.
316 * Otherwise an error is returned due to ongoing or failed
317 * initialization etc.
319 static inline int strong_try_module_get(struct module
*mod
)
321 BUG_ON(mod
&& mod
->state
== MODULE_STATE_UNFORMED
);
322 if (mod
&& mod
->state
== MODULE_STATE_COMING
)
324 if (try_module_get(mod
))
330 static inline void add_taint_module(struct module
*mod
, unsigned flag
,
331 enum lockdep_ok lockdep_ok
)
333 add_taint(flag
, lockdep_ok
);
334 set_bit(flag
, &mod
->taints
);
338 * A thread that wants to hold a reference to a module only while it
339 * is running can call this to safely exit. nfsd and lockd use this.
341 void __noreturn
__module_put_and_exit(struct module
*mod
, long code
)
346 EXPORT_SYMBOL(__module_put_and_exit
);
348 /* Find a module section: 0 means not found. */
349 static unsigned int find_sec(const struct load_info
*info
, const char *name
)
353 for (i
= 1; i
< info
->hdr
->e_shnum
; i
++) {
354 Elf_Shdr
*shdr
= &info
->sechdrs
[i
];
355 /* Alloc bit cleared means "ignore it." */
356 if ((shdr
->sh_flags
& SHF_ALLOC
)
357 && strcmp(info
->secstrings
+ shdr
->sh_name
, name
) == 0)
363 /* Find a module section, or NULL. */
364 static void *section_addr(const struct load_info
*info
, const char *name
)
366 /* Section 0 has sh_addr 0. */
367 return (void *)info
->sechdrs
[find_sec(info
, name
)].sh_addr
;
370 /* Find a module section, or NULL. Fill in number of "objects" in section. */
371 static void *section_objs(const struct load_info
*info
,
376 unsigned int sec
= find_sec(info
, name
);
378 /* Section 0 has sh_addr 0 and sh_size 0. */
379 *num
= info
->sechdrs
[sec
].sh_size
/ object_size
;
380 return (void *)info
->sechdrs
[sec
].sh_addr
;
383 /* Find a module section: 0 means not found. Ignores SHF_ALLOC flag. */
384 static unsigned int find_any_sec(const struct load_info
*info
, const char *name
)
388 for (i
= 1; i
< info
->hdr
->e_shnum
; i
++) {
389 Elf_Shdr
*shdr
= &info
->sechdrs
[i
];
390 if (strcmp(info
->secstrings
+ shdr
->sh_name
, name
) == 0)
397 * Find a module section, or NULL. Fill in number of "objects" in section.
398 * Ignores SHF_ALLOC flag.
400 static __maybe_unused
void *any_section_objs(const struct load_info
*info
,
405 unsigned int sec
= find_any_sec(info
, name
);
407 /* Section 0 has sh_addr 0 and sh_size 0. */
408 *num
= info
->sechdrs
[sec
].sh_size
/ object_size
;
409 return (void *)info
->sechdrs
[sec
].sh_addr
;
412 /* Provided by the linker */
413 extern const struct kernel_symbol __start___ksymtab
[];
414 extern const struct kernel_symbol __stop___ksymtab
[];
415 extern const struct kernel_symbol __start___ksymtab_gpl
[];
416 extern const struct kernel_symbol __stop___ksymtab_gpl
[];
417 extern const struct kernel_symbol __start___ksymtab_gpl_future
[];
418 extern const struct kernel_symbol __stop___ksymtab_gpl_future
[];
419 extern const s32 __start___kcrctab
[];
420 extern const s32 __start___kcrctab_gpl
[];
421 extern const s32 __start___kcrctab_gpl_future
[];
422 #ifdef CONFIG_UNUSED_SYMBOLS
423 extern const struct kernel_symbol __start___ksymtab_unused
[];
424 extern const struct kernel_symbol __stop___ksymtab_unused
[];
425 extern const struct kernel_symbol __start___ksymtab_unused_gpl
[];
426 extern const struct kernel_symbol __stop___ksymtab_unused_gpl
[];
427 extern const s32 __start___kcrctab_unused
[];
428 extern const s32 __start___kcrctab_unused_gpl
[];
431 #ifndef CONFIG_MODVERSIONS
432 #define symversion(base, idx) NULL
434 #define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
437 static bool each_symbol_in_section(const struct symsearch
*arr
,
438 unsigned int arrsize
,
439 struct module
*owner
,
440 bool (*fn
)(const struct symsearch
*syms
,
441 struct module
*owner
,
447 for (j
= 0; j
< arrsize
; j
++) {
448 if (fn(&arr
[j
], owner
, data
))
455 /* Returns true as soon as fn returns true, otherwise false. */
456 static bool each_symbol_section(bool (*fn
)(const struct symsearch
*arr
,
457 struct module
*owner
,
462 static const struct symsearch arr
[] = {
463 { __start___ksymtab
, __stop___ksymtab
, __start___kcrctab
,
464 NOT_GPL_ONLY
, false },
465 { __start___ksymtab_gpl
, __stop___ksymtab_gpl
,
466 __start___kcrctab_gpl
,
468 { __start___ksymtab_gpl_future
, __stop___ksymtab_gpl_future
,
469 __start___kcrctab_gpl_future
,
470 WILL_BE_GPL_ONLY
, false },
471 #ifdef CONFIG_UNUSED_SYMBOLS
472 { __start___ksymtab_unused
, __stop___ksymtab_unused
,
473 __start___kcrctab_unused
,
474 NOT_GPL_ONLY
, true },
475 { __start___ksymtab_unused_gpl
, __stop___ksymtab_unused_gpl
,
476 __start___kcrctab_unused_gpl
,
481 module_assert_mutex_or_preempt();
483 if (each_symbol_in_section(arr
, ARRAY_SIZE(arr
), NULL
, fn
, data
))
486 list_for_each_entry_rcu(mod
, &modules
, list
,
487 lockdep_is_held(&module_mutex
)) {
488 struct symsearch arr
[] = {
489 { mod
->syms
, mod
->syms
+ mod
->num_syms
, mod
->crcs
,
490 NOT_GPL_ONLY
, false },
491 { mod
->gpl_syms
, mod
->gpl_syms
+ mod
->num_gpl_syms
,
494 { mod
->gpl_future_syms
,
495 mod
->gpl_future_syms
+ mod
->num_gpl_future_syms
,
496 mod
->gpl_future_crcs
,
497 WILL_BE_GPL_ONLY
, false },
498 #ifdef CONFIG_UNUSED_SYMBOLS
500 mod
->unused_syms
+ mod
->num_unused_syms
,
502 NOT_GPL_ONLY
, true },
503 { mod
->unused_gpl_syms
,
504 mod
->unused_gpl_syms
+ mod
->num_unused_gpl_syms
,
505 mod
->unused_gpl_crcs
,
510 if (mod
->state
== MODULE_STATE_UNFORMED
)
513 if (each_symbol_in_section(arr
, ARRAY_SIZE(arr
), mod
, fn
, data
))
519 struct find_symbol_arg
{
526 struct module
*owner
;
528 const struct kernel_symbol
*sym
;
529 enum mod_license license
;
532 static bool check_exported_symbol(const struct symsearch
*syms
,
533 struct module
*owner
,
534 unsigned int symnum
, void *data
)
536 struct find_symbol_arg
*fsa
= data
;
539 if (syms
->license
== GPL_ONLY
)
541 if (syms
->license
== WILL_BE_GPL_ONLY
&& fsa
->warn
) {
542 pr_warn("Symbol %s is being used by a non-GPL module, "
543 "which will not be allowed in the future\n",
548 #ifdef CONFIG_UNUSED_SYMBOLS
549 if (syms
->unused
&& fsa
->warn
) {
550 pr_warn("Symbol %s is marked as UNUSED, however this module is "
551 "using it.\n", fsa
->name
);
552 pr_warn("This symbol will go away in the future.\n");
553 pr_warn("Please evaluate if this is the right api to use and "
554 "if it really is, submit a report to the linux kernel "
555 "mailing list together with submitting your code for "
561 fsa
->crc
= symversion(syms
->crcs
, symnum
);
562 fsa
->sym
= &syms
->start
[symnum
];
563 fsa
->license
= syms
->license
;
567 static unsigned long kernel_symbol_value(const struct kernel_symbol
*sym
)
569 #ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
570 return (unsigned long)offset_to_ptr(&sym
->value_offset
);
576 static const char *kernel_symbol_name(const struct kernel_symbol
*sym
)
578 #ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
579 return offset_to_ptr(&sym
->name_offset
);
585 static const char *kernel_symbol_namespace(const struct kernel_symbol
*sym
)
587 #ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
588 if (!sym
->namespace_offset
)
590 return offset_to_ptr(&sym
->namespace_offset
);
592 return sym
->namespace;
596 static int cmp_name(const void *name
, const void *sym
)
598 return strcmp(name
, kernel_symbol_name(sym
));
601 static bool find_exported_symbol_in_section(const struct symsearch
*syms
,
602 struct module
*owner
,
605 struct find_symbol_arg
*fsa
= data
;
606 struct kernel_symbol
*sym
;
608 sym
= bsearch(fsa
->name
, syms
->start
, syms
->stop
- syms
->start
,
609 sizeof(struct kernel_symbol
), cmp_name
);
611 if (sym
!= NULL
&& check_exported_symbol(syms
, owner
,
612 sym
- syms
->start
, data
))
619 * Find an exported symbol and return it, along with, (optional) crc and
620 * (optional) module which owns it. Needs preempt disabled or module_mutex.
622 static const struct kernel_symbol
*find_symbol(const char *name
,
623 struct module
**owner
,
625 enum mod_license
*license
,
629 struct find_symbol_arg fsa
;
635 if (each_symbol_section(find_exported_symbol_in_section
, &fsa
)) {
641 *license
= fsa
.license
;
645 pr_debug("Failed to find symbol %s\n", name
);
650 * Search for module by name: must hold module_mutex (or preempt disabled
651 * for read-only access).
653 static struct module
*find_module_all(const char *name
, size_t len
,
658 module_assert_mutex_or_preempt();
660 list_for_each_entry_rcu(mod
, &modules
, list
,
661 lockdep_is_held(&module_mutex
)) {
662 if (!even_unformed
&& mod
->state
== MODULE_STATE_UNFORMED
)
664 if (strlen(mod
->name
) == len
&& !memcmp(mod
->name
, name
, len
))
670 struct module
*find_module(const char *name
)
672 module_assert_mutex();
673 return find_module_all(name
, strlen(name
), false);
675 EXPORT_SYMBOL_GPL(find_module
);
679 static inline void __percpu
*mod_percpu(struct module
*mod
)
684 static int percpu_modalloc(struct module
*mod
, struct load_info
*info
)
686 Elf_Shdr
*pcpusec
= &info
->sechdrs
[info
->index
.pcpu
];
687 unsigned long align
= pcpusec
->sh_addralign
;
689 if (!pcpusec
->sh_size
)
692 if (align
> PAGE_SIZE
) {
693 pr_warn("%s: per-cpu alignment %li > %li\n",
694 mod
->name
, align
, PAGE_SIZE
);
698 mod
->percpu
= __alloc_reserved_percpu(pcpusec
->sh_size
, align
);
700 pr_warn("%s: Could not allocate %lu bytes percpu data\n",
701 mod
->name
, (unsigned long)pcpusec
->sh_size
);
704 mod
->percpu_size
= pcpusec
->sh_size
;
708 static void percpu_modfree(struct module
*mod
)
710 free_percpu(mod
->percpu
);
713 static unsigned int find_pcpusec(struct load_info
*info
)
715 return find_sec(info
, ".data..percpu");
718 static void percpu_modcopy(struct module
*mod
,
719 const void *from
, unsigned long size
)
723 for_each_possible_cpu(cpu
)
724 memcpy(per_cpu_ptr(mod
->percpu
, cpu
), from
, size
);
727 bool __is_module_percpu_address(unsigned long addr
, unsigned long *can_addr
)
734 list_for_each_entry_rcu(mod
, &modules
, list
) {
735 if (mod
->state
== MODULE_STATE_UNFORMED
)
737 if (!mod
->percpu_size
)
739 for_each_possible_cpu(cpu
) {
740 void *start
= per_cpu_ptr(mod
->percpu
, cpu
);
741 void *va
= (void *)addr
;
743 if (va
>= start
&& va
< start
+ mod
->percpu_size
) {
745 *can_addr
= (unsigned long) (va
- start
);
746 *can_addr
+= (unsigned long)
747 per_cpu_ptr(mod
->percpu
,
761 * is_module_percpu_address() - test whether address is from module static percpu
762 * @addr: address to test
764 * Test whether @addr belongs to module static percpu area.
766 * Return: %true if @addr is from module static percpu area
768 bool is_module_percpu_address(unsigned long addr
)
770 return __is_module_percpu_address(addr
, NULL
);
773 #else /* ... !CONFIG_SMP */
775 static inline void __percpu
*mod_percpu(struct module
*mod
)
779 static int percpu_modalloc(struct module
*mod
, struct load_info
*info
)
781 /* UP modules shouldn't have this section: ENOMEM isn't quite right */
782 if (info
->sechdrs
[info
->index
.pcpu
].sh_size
!= 0)
786 static inline void percpu_modfree(struct module
*mod
)
789 static unsigned int find_pcpusec(struct load_info
*info
)
793 static inline void percpu_modcopy(struct module
*mod
,
794 const void *from
, unsigned long size
)
796 /* pcpusec should be 0, and size of that section should be 0. */
799 bool is_module_percpu_address(unsigned long addr
)
804 bool __is_module_percpu_address(unsigned long addr
, unsigned long *can_addr
)
809 #endif /* CONFIG_SMP */
811 #define MODINFO_ATTR(field) \
812 static void setup_modinfo_##field(struct module *mod, const char *s) \
814 mod->field = kstrdup(s, GFP_KERNEL); \
816 static ssize_t show_modinfo_##field(struct module_attribute *mattr, \
817 struct module_kobject *mk, char *buffer) \
819 return scnprintf(buffer, PAGE_SIZE, "%s\n", mk->mod->field); \
821 static int modinfo_##field##_exists(struct module *mod) \
823 return mod->field != NULL; \
825 static void free_modinfo_##field(struct module *mod) \
830 static struct module_attribute modinfo_##field = { \
831 .attr = { .name = __stringify(field), .mode = 0444 }, \
832 .show = show_modinfo_##field, \
833 .setup = setup_modinfo_##field, \
834 .test = modinfo_##field##_exists, \
835 .free = free_modinfo_##field, \
838 MODINFO_ATTR(version
);
839 MODINFO_ATTR(srcversion
);
841 static char last_unloaded_module
[MODULE_NAME_LEN
+1];
843 #ifdef CONFIG_MODULE_UNLOAD
845 EXPORT_TRACEPOINT_SYMBOL(module_get
);
847 /* MODULE_REF_BASE is the base reference count by kmodule loader. */
848 #define MODULE_REF_BASE 1
850 /* Init the unload section of the module. */
851 static int module_unload_init(struct module
*mod
)
854 * Initialize reference counter to MODULE_REF_BASE.
855 * refcnt == 0 means module is going.
857 atomic_set(&mod
->refcnt
, MODULE_REF_BASE
);
859 INIT_LIST_HEAD(&mod
->source_list
);
860 INIT_LIST_HEAD(&mod
->target_list
);
862 /* Hold reference count during initialization. */
863 atomic_inc(&mod
->refcnt
);
868 /* Does a already use b? */
869 static int already_uses(struct module
*a
, struct module
*b
)
871 struct module_use
*use
;
873 list_for_each_entry(use
, &b
->source_list
, source_list
) {
874 if (use
->source
== a
) {
875 pr_debug("%s uses %s!\n", a
->name
, b
->name
);
879 pr_debug("%s does not use %s!\n", a
->name
, b
->name
);
885 * - we add 'a' as a "source", 'b' as a "target" of module use
886 * - the module_use is added to the list of 'b' sources (so
887 * 'b' can walk the list to see who sourced them), and of 'a'
888 * targets (so 'a' can see what modules it targets).
890 static int add_module_usage(struct module
*a
, struct module
*b
)
892 struct module_use
*use
;
894 pr_debug("Allocating new usage for %s.\n", a
->name
);
895 use
= kmalloc(sizeof(*use
), GFP_ATOMIC
);
901 list_add(&use
->source_list
, &b
->source_list
);
902 list_add(&use
->target_list
, &a
->target_list
);
906 /* Module a uses b: caller needs module_mutex() */
907 static int ref_module(struct module
*a
, struct module
*b
)
911 if (b
== NULL
|| already_uses(a
, b
))
914 /* If module isn't available, we fail. */
915 err
= strong_try_module_get(b
);
919 err
= add_module_usage(a
, b
);
927 /* Clear the unload stuff of the module. */
928 static void module_unload_free(struct module
*mod
)
930 struct module_use
*use
, *tmp
;
932 mutex_lock(&module_mutex
);
933 list_for_each_entry_safe(use
, tmp
, &mod
->target_list
, target_list
) {
934 struct module
*i
= use
->target
;
935 pr_debug("%s unusing %s\n", mod
->name
, i
->name
);
937 list_del(&use
->source_list
);
938 list_del(&use
->target_list
);
941 mutex_unlock(&module_mutex
);
944 #ifdef CONFIG_MODULE_FORCE_UNLOAD
945 static inline int try_force_unload(unsigned int flags
)
947 int ret
= (flags
& O_TRUNC
);
949 add_taint(TAINT_FORCED_RMMOD
, LOCKDEP_NOW_UNRELIABLE
);
953 static inline int try_force_unload(unsigned int flags
)
957 #endif /* CONFIG_MODULE_FORCE_UNLOAD */
959 /* Try to release refcount of module, 0 means success. */
960 static int try_release_module_ref(struct module
*mod
)
964 /* Try to decrement refcnt which we set at loading */
965 ret
= atomic_sub_return(MODULE_REF_BASE
, &mod
->refcnt
);
968 /* Someone can put this right now, recover with checking */
969 ret
= atomic_add_unless(&mod
->refcnt
, MODULE_REF_BASE
, 0);
974 static int try_stop_module(struct module
*mod
, int flags
, int *forced
)
976 /* If it's not unused, quit unless we're forcing. */
977 if (try_release_module_ref(mod
) != 0) {
978 *forced
= try_force_unload(flags
);
983 /* Mark it as dying. */
984 mod
->state
= MODULE_STATE_GOING
;
990 * module_refcount() - return the refcount or -1 if unloading
991 * @mod: the module we're checking
994 * -1 if the module is in the process of unloading
995 * otherwise the number of references in the kernel to the module
997 int module_refcount(struct module
*mod
)
999 return atomic_read(&mod
->refcnt
) - MODULE_REF_BASE
;
1001 EXPORT_SYMBOL(module_refcount
);
1003 /* This exists whether we can unload or not */
1004 static void free_module(struct module
*mod
);
1006 SYSCALL_DEFINE2(delete_module
, const char __user
*, name_user
,
1007 unsigned int, flags
)
1010 char name
[MODULE_NAME_LEN
];
1011 int ret
, forced
= 0;
1013 if (!capable(CAP_SYS_MODULE
) || modules_disabled
)
1016 if (strncpy_from_user(name
, name_user
, MODULE_NAME_LEN
-1) < 0)
1018 name
[MODULE_NAME_LEN
-1] = '\0';
1020 audit_log_kern_module(name
);
1022 if (mutex_lock_interruptible(&module_mutex
) != 0)
1025 mod
= find_module(name
);
1031 if (!list_empty(&mod
->source_list
)) {
1032 /* Other modules depend on us: get rid of them first. */
1037 /* Doing init or already dying? */
1038 if (mod
->state
!= MODULE_STATE_LIVE
) {
1039 /* FIXME: if (force), slam module count damn the torpedoes */
1040 pr_debug("%s already dying\n", mod
->name
);
1045 /* If it has an init func, it must have an exit func to unload */
1046 if (mod
->init
&& !mod
->exit
) {
1047 forced
= try_force_unload(flags
);
1049 /* This module can't be removed */
1055 /* Stop the machine so refcounts can't move and disable module. */
1056 ret
= try_stop_module(mod
, flags
, &forced
);
1060 mutex_unlock(&module_mutex
);
1061 /* Final destruction now no one is using it. */
1062 if (mod
->exit
!= NULL
)
1064 blocking_notifier_call_chain(&module_notify_list
,
1065 MODULE_STATE_GOING
, mod
);
1066 klp_module_going(mod
);
1067 ftrace_release_mod(mod
);
1069 async_synchronize_full();
1071 /* Store the name of the last unloaded module for diagnostic purposes */
1072 strlcpy(last_unloaded_module
, mod
->name
, sizeof(last_unloaded_module
));
1075 /* someone could wait for the module in add_unformed_module() */
1076 wake_up_all(&module_wq
);
1079 mutex_unlock(&module_mutex
);
1083 static inline void print_unload_info(struct seq_file
*m
, struct module
*mod
)
1085 struct module_use
*use
;
1086 int printed_something
= 0;
1088 seq_printf(m
, " %i ", module_refcount(mod
));
1091 * Always include a trailing , so userspace can differentiate
1092 * between this and the old multi-field proc format.
1094 list_for_each_entry(use
, &mod
->source_list
, source_list
) {
1095 printed_something
= 1;
1096 seq_printf(m
, "%s,", use
->source
->name
);
1099 if (mod
->init
!= NULL
&& mod
->exit
== NULL
) {
1100 printed_something
= 1;
1101 seq_puts(m
, "[permanent],");
1104 if (!printed_something
)
1108 void __symbol_put(const char *symbol
)
1110 struct module
*owner
;
1113 if (!find_symbol(symbol
, &owner
, NULL
, NULL
, true, false))
1118 EXPORT_SYMBOL(__symbol_put
);
1120 /* Note this assumes addr is a function, which it currently always is. */
1121 void symbol_put_addr(void *addr
)
1123 struct module
*modaddr
;
1124 unsigned long a
= (unsigned long)dereference_function_descriptor(addr
);
1126 if (core_kernel_text(a
))
1130 * Even though we hold a reference on the module; we still need to
1131 * disable preemption in order to safely traverse the data structure.
1134 modaddr
= __module_text_address(a
);
1136 module_put(modaddr
);
1139 EXPORT_SYMBOL_GPL(symbol_put_addr
);
1141 static ssize_t
show_refcnt(struct module_attribute
*mattr
,
1142 struct module_kobject
*mk
, char *buffer
)
1144 return sprintf(buffer
, "%i\n", module_refcount(mk
->mod
));
1147 static struct module_attribute modinfo_refcnt
=
1148 __ATTR(refcnt
, 0444, show_refcnt
, NULL
);
1150 void __module_get(struct module
*module
)
1154 atomic_inc(&module
->refcnt
);
1155 trace_module_get(module
, _RET_IP_
);
1159 EXPORT_SYMBOL(__module_get
);
1161 bool try_module_get(struct module
*module
)
1167 /* Note: here, we can fail to get a reference */
1168 if (likely(module_is_live(module
) &&
1169 atomic_inc_not_zero(&module
->refcnt
) != 0))
1170 trace_module_get(module
, _RET_IP_
);
1178 EXPORT_SYMBOL(try_module_get
);
1180 void module_put(struct module
*module
)
1186 ret
= atomic_dec_if_positive(&module
->refcnt
);
1187 WARN_ON(ret
< 0); /* Failed to put refcount */
1188 trace_module_put(module
, _RET_IP_
);
1192 EXPORT_SYMBOL(module_put
);
1194 #else /* !CONFIG_MODULE_UNLOAD */
1195 static inline void print_unload_info(struct seq_file
*m
, struct module
*mod
)
1197 /* We don't know the usage count, or what modules are using. */
1198 seq_puts(m
, " - -");
1201 static inline void module_unload_free(struct module
*mod
)
1205 static int ref_module(struct module
*a
, struct module
*b
)
1207 return strong_try_module_get(b
);
1210 static inline int module_unload_init(struct module
*mod
)
1214 #endif /* CONFIG_MODULE_UNLOAD */
1216 static size_t module_flags_taint(struct module
*mod
, char *buf
)
1221 for (i
= 0; i
< TAINT_FLAGS_COUNT
; i
++) {
1222 if (taint_flags
[i
].module
&& test_bit(i
, &mod
->taints
))
1223 buf
[l
++] = taint_flags
[i
].c_true
;
1229 static ssize_t
show_initstate(struct module_attribute
*mattr
,
1230 struct module_kobject
*mk
, char *buffer
)
1232 const char *state
= "unknown";
1234 switch (mk
->mod
->state
) {
1235 case MODULE_STATE_LIVE
:
1238 case MODULE_STATE_COMING
:
1241 case MODULE_STATE_GOING
:
1247 return sprintf(buffer
, "%s\n", state
);
1250 static struct module_attribute modinfo_initstate
=
1251 __ATTR(initstate
, 0444, show_initstate
, NULL
);
1253 static ssize_t
store_uevent(struct module_attribute
*mattr
,
1254 struct module_kobject
*mk
,
1255 const char *buffer
, size_t count
)
1259 rc
= kobject_synth_uevent(&mk
->kobj
, buffer
, count
);
1260 return rc
? rc
: count
;
1263 struct module_attribute module_uevent
=
1264 __ATTR(uevent
, 0200, NULL
, store_uevent
);
1266 static ssize_t
show_coresize(struct module_attribute
*mattr
,
1267 struct module_kobject
*mk
, char *buffer
)
1269 return sprintf(buffer
, "%u\n", mk
->mod
->core_layout
.size
);
1272 static struct module_attribute modinfo_coresize
=
1273 __ATTR(coresize
, 0444, show_coresize
, NULL
);
1275 static ssize_t
show_initsize(struct module_attribute
*mattr
,
1276 struct module_kobject
*mk
, char *buffer
)
1278 return sprintf(buffer
, "%u\n", mk
->mod
->init_layout
.size
);
1281 static struct module_attribute modinfo_initsize
=
1282 __ATTR(initsize
, 0444, show_initsize
, NULL
);
1284 static ssize_t
show_taint(struct module_attribute
*mattr
,
1285 struct module_kobject
*mk
, char *buffer
)
1289 l
= module_flags_taint(mk
->mod
, buffer
);
1294 static struct module_attribute modinfo_taint
=
1295 __ATTR(taint
, 0444, show_taint
, NULL
);
1297 static struct module_attribute
*modinfo_attrs
[] = {
1300 &modinfo_srcversion
,
1305 #ifdef CONFIG_MODULE_UNLOAD
1311 static const char vermagic
[] = VERMAGIC_STRING
;
1313 static int try_to_force_load(struct module
*mod
, const char *reason
)
1315 #ifdef CONFIG_MODULE_FORCE_LOAD
1316 if (!test_taint(TAINT_FORCED_MODULE
))
1317 pr_warn("%s: %s: kernel tainted.\n", mod
->name
, reason
);
1318 add_taint_module(mod
, TAINT_FORCED_MODULE
, LOCKDEP_NOW_UNRELIABLE
);
1325 #ifdef CONFIG_MODVERSIONS
1327 static u32
resolve_rel_crc(const s32
*crc
)
1329 return *(u32
*)((void *)crc
+ *crc
);
1332 static int check_version(const struct load_info
*info
,
1333 const char *symname
,
1337 Elf_Shdr
*sechdrs
= info
->sechdrs
;
1338 unsigned int versindex
= info
->index
.vers
;
1339 unsigned int i
, num_versions
;
1340 struct modversion_info
*versions
;
1342 /* Exporting module didn't supply crcs? OK, we're already tainted. */
1346 /* No versions at all? modprobe --force does this. */
1348 return try_to_force_load(mod
, symname
) == 0;
1350 versions
= (void *) sechdrs
[versindex
].sh_addr
;
1351 num_versions
= sechdrs
[versindex
].sh_size
1352 / sizeof(struct modversion_info
);
1354 for (i
= 0; i
< num_versions
; i
++) {
1357 if (strcmp(versions
[i
].name
, symname
) != 0)
1360 if (IS_ENABLED(CONFIG_MODULE_REL_CRCS
))
1361 crcval
= resolve_rel_crc(crc
);
1364 if (versions
[i
].crc
== crcval
)
1366 pr_debug("Found checksum %X vs module %lX\n",
1367 crcval
, versions
[i
].crc
);
1371 /* Broken toolchain. Warn once, then let it go.. */
1372 pr_warn_once("%s: no symbol version for %s\n", info
->name
, symname
);
1376 pr_warn("%s: disagrees about version of symbol %s\n",
1377 info
->name
, symname
);
1381 static inline int check_modstruct_version(const struct load_info
*info
,
1387 * Since this should be found in kernel (which can't be removed), no
1388 * locking is necessary -- use preempt_disable() to placate lockdep.
1391 if (!find_symbol("module_layout", NULL
, &crc
, NULL
, true, false)) {
1396 return check_version(info
, "module_layout", mod
, crc
);
1399 /* First part is kernel version, which we ignore if module has crcs. */
1400 static inline int same_magic(const char *amagic
, const char *bmagic
,
1404 amagic
+= strcspn(amagic
, " ");
1405 bmagic
+= strcspn(bmagic
, " ");
1407 return strcmp(amagic
, bmagic
) == 0;
1410 static inline int check_version(const struct load_info
*info
,
1411 const char *symname
,
1418 static inline int check_modstruct_version(const struct load_info
*info
,
1424 static inline int same_magic(const char *amagic
, const char *bmagic
,
1427 return strcmp(amagic
, bmagic
) == 0;
1429 #endif /* CONFIG_MODVERSIONS */
1431 static char *get_modinfo(const struct load_info
*info
, const char *tag
);
1432 static char *get_next_modinfo(const struct load_info
*info
, const char *tag
,
1435 static int verify_namespace_is_imported(const struct load_info
*info
,
1436 const struct kernel_symbol
*sym
,
1439 const char *namespace;
1440 char *imported_namespace
;
1442 namespace = kernel_symbol_namespace(sym
);
1443 if (namespace && namespace[0]) {
1444 imported_namespace
= get_modinfo(info
, "import_ns");
1445 while (imported_namespace
) {
1446 if (strcmp(namespace, imported_namespace
) == 0)
1448 imported_namespace
= get_next_modinfo(
1449 info
, "import_ns", imported_namespace
);
1451 #ifdef CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS
1456 "%s: module uses symbol (%s) from namespace %s, but does not import it.\n",
1457 mod
->name
, kernel_symbol_name(sym
), namespace);
1458 #ifndef CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS
1465 static bool inherit_taint(struct module
*mod
, struct module
*owner
)
1467 if (!owner
|| !test_bit(TAINT_PROPRIETARY_MODULE
, &owner
->taints
))
1470 if (mod
->using_gplonly_symbols
) {
1471 pr_err("%s: module using GPL-only symbols uses symbols from proprietary module %s.\n",
1472 mod
->name
, owner
->name
);
1476 if (!test_bit(TAINT_PROPRIETARY_MODULE
, &mod
->taints
)) {
1477 pr_warn("%s: module uses symbols from proprietary module %s, inheriting taint.\n",
1478 mod
->name
, owner
->name
);
1479 set_bit(TAINT_PROPRIETARY_MODULE
, &mod
->taints
);
1484 /* Resolve a symbol for this module. I.e. if we find one, record usage. */
1485 static const struct kernel_symbol
*resolve_symbol(struct module
*mod
,
1486 const struct load_info
*info
,
1490 struct module
*owner
;
1491 const struct kernel_symbol
*sym
;
1493 enum mod_license license
;
1497 * The module_mutex should not be a heavily contended lock;
1498 * if we get the occasional sleep here, we'll go an extra iteration
1499 * in the wait_event_interruptible(), which is harmless.
1501 sched_annotate_sleep();
1502 mutex_lock(&module_mutex
);
1503 sym
= find_symbol(name
, &owner
, &crc
, &license
,
1504 !(mod
->taints
& (1 << TAINT_PROPRIETARY_MODULE
)), true);
1508 if (license
== GPL_ONLY
)
1509 mod
->using_gplonly_symbols
= true;
1511 if (!inherit_taint(mod
, owner
)) {
1516 if (!check_version(info
, name
, mod
, crc
)) {
1517 sym
= ERR_PTR(-EINVAL
);
1521 err
= verify_namespace_is_imported(info
, sym
, mod
);
1527 err
= ref_module(mod
, owner
);
1534 /* We must make copy under the lock if we failed to get ref. */
1535 strncpy(ownername
, module_name(owner
), MODULE_NAME_LEN
);
1537 mutex_unlock(&module_mutex
);
1541 static const struct kernel_symbol
*
1542 resolve_symbol_wait(struct module
*mod
,
1543 const struct load_info
*info
,
1546 const struct kernel_symbol
*ksym
;
1547 char owner
[MODULE_NAME_LEN
];
1549 if (wait_event_interruptible_timeout(module_wq
,
1550 !IS_ERR(ksym
= resolve_symbol(mod
, info
, name
, owner
))
1551 || PTR_ERR(ksym
) != -EBUSY
,
1553 pr_warn("%s: gave up waiting for init of module %s.\n",
1560 * /sys/module/foo/sections stuff
1561 * J. Corbet <corbet@lwn.net>
1565 #ifdef CONFIG_KALLSYMS
1566 static inline bool sect_empty(const Elf_Shdr
*sect
)
1568 return !(sect
->sh_flags
& SHF_ALLOC
) || sect
->sh_size
== 0;
1571 struct module_sect_attr
{
1572 struct bin_attribute battr
;
1573 unsigned long address
;
1576 struct module_sect_attrs
{
1577 struct attribute_group grp
;
1578 unsigned int nsections
;
1579 struct module_sect_attr attrs
[];
1582 #define MODULE_SECT_READ_SIZE (3 /* "0x", "\n" */ + (BITS_PER_LONG / 4))
1583 static ssize_t
module_sect_read(struct file
*file
, struct kobject
*kobj
,
1584 struct bin_attribute
*battr
,
1585 char *buf
, loff_t pos
, size_t count
)
1587 struct module_sect_attr
*sattr
=
1588 container_of(battr
, struct module_sect_attr
, battr
);
1589 char bounce
[MODULE_SECT_READ_SIZE
+ 1];
1596 * Since we're a binary read handler, we must account for the
1597 * trailing NUL byte that sprintf will write: if "buf" is
1598 * too small to hold the NUL, or the NUL is exactly the last
1599 * byte, the read will look like it got truncated by one byte.
1600 * Since there is no way to ask sprintf nicely to not write
1601 * the NUL, we have to use a bounce buffer.
1603 wrote
= scnprintf(bounce
, sizeof(bounce
), "0x%px\n",
1604 kallsyms_show_value(file
->f_cred
)
1605 ? (void *)sattr
->address
: NULL
);
1606 count
= min(count
, wrote
);
1607 memcpy(buf
, bounce
, count
);
1612 static void free_sect_attrs(struct module_sect_attrs
*sect_attrs
)
1614 unsigned int section
;
1616 for (section
= 0; section
< sect_attrs
->nsections
; section
++)
1617 kfree(sect_attrs
->attrs
[section
].battr
.attr
.name
);
1621 static void add_sect_attrs(struct module
*mod
, const struct load_info
*info
)
1623 unsigned int nloaded
= 0, i
, size
[2];
1624 struct module_sect_attrs
*sect_attrs
;
1625 struct module_sect_attr
*sattr
;
1626 struct bin_attribute
**gattr
;
1628 /* Count loaded sections and allocate structures */
1629 for (i
= 0; i
< info
->hdr
->e_shnum
; i
++)
1630 if (!sect_empty(&info
->sechdrs
[i
]))
1632 size
[0] = ALIGN(struct_size(sect_attrs
, attrs
, nloaded
),
1633 sizeof(sect_attrs
->grp
.bin_attrs
[0]));
1634 size
[1] = (nloaded
+ 1) * sizeof(sect_attrs
->grp
.bin_attrs
[0]);
1635 sect_attrs
= kzalloc(size
[0] + size
[1], GFP_KERNEL
);
1636 if (sect_attrs
== NULL
)
1639 /* Setup section attributes. */
1640 sect_attrs
->grp
.name
= "sections";
1641 sect_attrs
->grp
.bin_attrs
= (void *)sect_attrs
+ size
[0];
1643 sect_attrs
->nsections
= 0;
1644 sattr
= §_attrs
->attrs
[0];
1645 gattr
= §_attrs
->grp
.bin_attrs
[0];
1646 for (i
= 0; i
< info
->hdr
->e_shnum
; i
++) {
1647 Elf_Shdr
*sec
= &info
->sechdrs
[i
];
1648 if (sect_empty(sec
))
1650 sysfs_bin_attr_init(&sattr
->battr
);
1651 sattr
->address
= sec
->sh_addr
;
1652 sattr
->battr
.attr
.name
=
1653 kstrdup(info
->secstrings
+ sec
->sh_name
, GFP_KERNEL
);
1654 if (sattr
->battr
.attr
.name
== NULL
)
1656 sect_attrs
->nsections
++;
1657 sattr
->battr
.read
= module_sect_read
;
1658 sattr
->battr
.size
= MODULE_SECT_READ_SIZE
;
1659 sattr
->battr
.attr
.mode
= 0400;
1660 *(gattr
++) = &(sattr
++)->battr
;
1664 if (sysfs_create_group(&mod
->mkobj
.kobj
, §_attrs
->grp
))
1667 mod
->sect_attrs
= sect_attrs
;
1670 free_sect_attrs(sect_attrs
);
1673 static void remove_sect_attrs(struct module
*mod
)
1675 if (mod
->sect_attrs
) {
1676 sysfs_remove_group(&mod
->mkobj
.kobj
,
1677 &mod
->sect_attrs
->grp
);
1679 * We are positive that no one is using any sect attrs
1680 * at this point. Deallocate immediately.
1682 free_sect_attrs(mod
->sect_attrs
);
1683 mod
->sect_attrs
= NULL
;
1688 * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections.
1691 struct module_notes_attrs
{
1692 struct kobject
*dir
;
1694 struct bin_attribute attrs
[];
1697 static ssize_t
module_notes_read(struct file
*filp
, struct kobject
*kobj
,
1698 struct bin_attribute
*bin_attr
,
1699 char *buf
, loff_t pos
, size_t count
)
1702 * The caller checked the pos and count against our size.
1704 memcpy(buf
, bin_attr
->private + pos
, count
);
1708 static void free_notes_attrs(struct module_notes_attrs
*notes_attrs
,
1711 if (notes_attrs
->dir
) {
1713 sysfs_remove_bin_file(notes_attrs
->dir
,
1714 ¬es_attrs
->attrs
[i
]);
1715 kobject_put(notes_attrs
->dir
);
1720 static void add_notes_attrs(struct module
*mod
, const struct load_info
*info
)
1722 unsigned int notes
, loaded
, i
;
1723 struct module_notes_attrs
*notes_attrs
;
1724 struct bin_attribute
*nattr
;
1726 /* failed to create section attributes, so can't create notes */
1727 if (!mod
->sect_attrs
)
1730 /* Count notes sections and allocate structures. */
1732 for (i
= 0; i
< info
->hdr
->e_shnum
; i
++)
1733 if (!sect_empty(&info
->sechdrs
[i
]) &&
1734 (info
->sechdrs
[i
].sh_type
== SHT_NOTE
))
1740 notes_attrs
= kzalloc(struct_size(notes_attrs
, attrs
, notes
),
1742 if (notes_attrs
== NULL
)
1745 notes_attrs
->notes
= notes
;
1746 nattr
= ¬es_attrs
->attrs
[0];
1747 for (loaded
= i
= 0; i
< info
->hdr
->e_shnum
; ++i
) {
1748 if (sect_empty(&info
->sechdrs
[i
]))
1750 if (info
->sechdrs
[i
].sh_type
== SHT_NOTE
) {
1751 sysfs_bin_attr_init(nattr
);
1752 nattr
->attr
.name
= mod
->sect_attrs
->attrs
[loaded
].battr
.attr
.name
;
1753 nattr
->attr
.mode
= S_IRUGO
;
1754 nattr
->size
= info
->sechdrs
[i
].sh_size
;
1755 nattr
->private = (void *) info
->sechdrs
[i
].sh_addr
;
1756 nattr
->read
= module_notes_read
;
1762 notes_attrs
->dir
= kobject_create_and_add("notes", &mod
->mkobj
.kobj
);
1763 if (!notes_attrs
->dir
)
1766 for (i
= 0; i
< notes
; ++i
)
1767 if (sysfs_create_bin_file(notes_attrs
->dir
,
1768 ¬es_attrs
->attrs
[i
]))
1771 mod
->notes_attrs
= notes_attrs
;
1775 free_notes_attrs(notes_attrs
, i
);
1778 static void remove_notes_attrs(struct module
*mod
)
1780 if (mod
->notes_attrs
)
1781 free_notes_attrs(mod
->notes_attrs
, mod
->notes_attrs
->notes
);
1786 static inline void add_sect_attrs(struct module
*mod
,
1787 const struct load_info
*info
)
1791 static inline void remove_sect_attrs(struct module
*mod
)
1795 static inline void add_notes_attrs(struct module
*mod
,
1796 const struct load_info
*info
)
1800 static inline void remove_notes_attrs(struct module
*mod
)
1803 #endif /* CONFIG_KALLSYMS */
1805 static void del_usage_links(struct module
*mod
)
1807 #ifdef CONFIG_MODULE_UNLOAD
1808 struct module_use
*use
;
1810 mutex_lock(&module_mutex
);
1811 list_for_each_entry(use
, &mod
->target_list
, target_list
)
1812 sysfs_remove_link(use
->target
->holders_dir
, mod
->name
);
1813 mutex_unlock(&module_mutex
);
1817 static int add_usage_links(struct module
*mod
)
1820 #ifdef CONFIG_MODULE_UNLOAD
1821 struct module_use
*use
;
1823 mutex_lock(&module_mutex
);
1824 list_for_each_entry(use
, &mod
->target_list
, target_list
) {
1825 ret
= sysfs_create_link(use
->target
->holders_dir
,
1826 &mod
->mkobj
.kobj
, mod
->name
);
1830 mutex_unlock(&module_mutex
);
1832 del_usage_links(mod
);
1837 static void module_remove_modinfo_attrs(struct module
*mod
, int end
);
1839 static int module_add_modinfo_attrs(struct module
*mod
)
1841 struct module_attribute
*attr
;
1842 struct module_attribute
*temp_attr
;
1846 mod
->modinfo_attrs
= kzalloc((sizeof(struct module_attribute
) *
1847 (ARRAY_SIZE(modinfo_attrs
) + 1)),
1849 if (!mod
->modinfo_attrs
)
1852 temp_attr
= mod
->modinfo_attrs
;
1853 for (i
= 0; (attr
= modinfo_attrs
[i
]); i
++) {
1854 if (!attr
->test
|| attr
->test(mod
)) {
1855 memcpy(temp_attr
, attr
, sizeof(*temp_attr
));
1856 sysfs_attr_init(&temp_attr
->attr
);
1857 error
= sysfs_create_file(&mod
->mkobj
.kobj
,
1869 module_remove_modinfo_attrs(mod
, --i
);
1871 kfree(mod
->modinfo_attrs
);
1875 static void module_remove_modinfo_attrs(struct module
*mod
, int end
)
1877 struct module_attribute
*attr
;
1880 for (i
= 0; (attr
= &mod
->modinfo_attrs
[i
]); i
++) {
1881 if (end
>= 0 && i
> end
)
1883 /* pick a field to test for end of list */
1884 if (!attr
->attr
.name
)
1886 sysfs_remove_file(&mod
->mkobj
.kobj
, &attr
->attr
);
1890 kfree(mod
->modinfo_attrs
);
1893 static void mod_kobject_put(struct module
*mod
)
1895 DECLARE_COMPLETION_ONSTACK(c
);
1896 mod
->mkobj
.kobj_completion
= &c
;
1897 kobject_put(&mod
->mkobj
.kobj
);
1898 wait_for_completion(&c
);
1901 static int mod_sysfs_init(struct module
*mod
)
1904 struct kobject
*kobj
;
1906 if (!module_sysfs_initialized
) {
1907 pr_err("%s: module sysfs not initialized\n", mod
->name
);
1912 kobj
= kset_find_obj(module_kset
, mod
->name
);
1914 pr_err("%s: module is already loaded\n", mod
->name
);
1920 mod
->mkobj
.mod
= mod
;
1922 memset(&mod
->mkobj
.kobj
, 0, sizeof(mod
->mkobj
.kobj
));
1923 mod
->mkobj
.kobj
.kset
= module_kset
;
1924 err
= kobject_init_and_add(&mod
->mkobj
.kobj
, &module_ktype
, NULL
,
1927 mod_kobject_put(mod
);
1933 static int mod_sysfs_setup(struct module
*mod
,
1934 const struct load_info
*info
,
1935 struct kernel_param
*kparam
,
1936 unsigned int num_params
)
1940 err
= mod_sysfs_init(mod
);
1944 mod
->holders_dir
= kobject_create_and_add("holders", &mod
->mkobj
.kobj
);
1945 if (!mod
->holders_dir
) {
1950 err
= module_param_sysfs_setup(mod
, kparam
, num_params
);
1952 goto out_unreg_holders
;
1954 err
= module_add_modinfo_attrs(mod
);
1956 goto out_unreg_param
;
1958 err
= add_usage_links(mod
);
1960 goto out_unreg_modinfo_attrs
;
1962 add_sect_attrs(mod
, info
);
1963 add_notes_attrs(mod
, info
);
1967 out_unreg_modinfo_attrs
:
1968 module_remove_modinfo_attrs(mod
, -1);
1970 module_param_sysfs_remove(mod
);
1972 kobject_put(mod
->holders_dir
);
1974 mod_kobject_put(mod
);
1979 static void mod_sysfs_fini(struct module
*mod
)
1981 remove_notes_attrs(mod
);
1982 remove_sect_attrs(mod
);
1983 mod_kobject_put(mod
);
1986 static void init_param_lock(struct module
*mod
)
1988 mutex_init(&mod
->param_lock
);
1990 #else /* !CONFIG_SYSFS */
1992 static int mod_sysfs_setup(struct module
*mod
,
1993 const struct load_info
*info
,
1994 struct kernel_param
*kparam
,
1995 unsigned int num_params
)
2000 static void mod_sysfs_fini(struct module
*mod
)
2004 static void module_remove_modinfo_attrs(struct module
*mod
, int end
)
2008 static void del_usage_links(struct module
*mod
)
2012 static void init_param_lock(struct module
*mod
)
2015 #endif /* CONFIG_SYSFS */
2017 static void mod_sysfs_teardown(struct module
*mod
)
2019 del_usage_links(mod
);
2020 module_remove_modinfo_attrs(mod
, -1);
2021 module_param_sysfs_remove(mod
);
2022 kobject_put(mod
->mkobj
.drivers_dir
);
2023 kobject_put(mod
->holders_dir
);
2024 mod_sysfs_fini(mod
);
2028 * LKM RO/NX protection: protect module's text/ro-data
2029 * from modification and any data from execution.
2031 * General layout of module is:
2032 * [text] [read-only-data] [ro-after-init] [writable data]
2033 * text_size -----^ ^ ^ ^
2034 * ro_size ------------------------| | |
2035 * ro_after_init_size -----------------------------| |
2036 * size -----------------------------------------------------------|
2038 * These values are always page-aligned (as is base)
2042 * Since some arches are moving towards PAGE_KERNEL module allocations instead
2043 * of PAGE_KERNEL_EXEC, keep frob_text() and module_enable_x() outside of the
2044 * CONFIG_STRICT_MODULE_RWX block below because they are needed regardless of
2045 * whether we are strict.
2047 #ifdef CONFIG_ARCH_HAS_STRICT_MODULE_RWX
2048 static void frob_text(const struct module_layout
*layout
,
2049 int (*set_memory
)(unsigned long start
, int num_pages
))
2051 BUG_ON((unsigned long)layout
->base
& (PAGE_SIZE
-1));
2052 BUG_ON((unsigned long)layout
->text_size
& (PAGE_SIZE
-1));
2053 set_memory((unsigned long)layout
->base
,
2054 layout
->text_size
>> PAGE_SHIFT
);
2057 static void module_enable_x(const struct module
*mod
)
2059 frob_text(&mod
->core_layout
, set_memory_x
);
2060 frob_text(&mod
->init_layout
, set_memory_x
);
2062 #else /* !CONFIG_ARCH_HAS_STRICT_MODULE_RWX */
2063 static void module_enable_x(const struct module
*mod
) { }
2064 #endif /* CONFIG_ARCH_HAS_STRICT_MODULE_RWX */
2066 #ifdef CONFIG_STRICT_MODULE_RWX
2067 static void frob_rodata(const struct module_layout
*layout
,
2068 int (*set_memory
)(unsigned long start
, int num_pages
))
2070 BUG_ON((unsigned long)layout
->base
& (PAGE_SIZE
-1));
2071 BUG_ON((unsigned long)layout
->text_size
& (PAGE_SIZE
-1));
2072 BUG_ON((unsigned long)layout
->ro_size
& (PAGE_SIZE
-1));
2073 set_memory((unsigned long)layout
->base
+ layout
->text_size
,
2074 (layout
->ro_size
- layout
->text_size
) >> PAGE_SHIFT
);
2077 static void frob_ro_after_init(const struct module_layout
*layout
,
2078 int (*set_memory
)(unsigned long start
, int num_pages
))
2080 BUG_ON((unsigned long)layout
->base
& (PAGE_SIZE
-1));
2081 BUG_ON((unsigned long)layout
->ro_size
& (PAGE_SIZE
-1));
2082 BUG_ON((unsigned long)layout
->ro_after_init_size
& (PAGE_SIZE
-1));
2083 set_memory((unsigned long)layout
->base
+ layout
->ro_size
,
2084 (layout
->ro_after_init_size
- layout
->ro_size
) >> PAGE_SHIFT
);
2087 static void frob_writable_data(const struct module_layout
*layout
,
2088 int (*set_memory
)(unsigned long start
, int num_pages
))
2090 BUG_ON((unsigned long)layout
->base
& (PAGE_SIZE
-1));
2091 BUG_ON((unsigned long)layout
->ro_after_init_size
& (PAGE_SIZE
-1));
2092 BUG_ON((unsigned long)layout
->size
& (PAGE_SIZE
-1));
2093 set_memory((unsigned long)layout
->base
+ layout
->ro_after_init_size
,
2094 (layout
->size
- layout
->ro_after_init_size
) >> PAGE_SHIFT
);
2097 static void module_enable_ro(const struct module
*mod
, bool after_init
)
2099 if (!rodata_enabled
)
2102 set_vm_flush_reset_perms(mod
->core_layout
.base
);
2103 set_vm_flush_reset_perms(mod
->init_layout
.base
);
2104 frob_text(&mod
->core_layout
, set_memory_ro
);
2106 frob_rodata(&mod
->core_layout
, set_memory_ro
);
2107 frob_text(&mod
->init_layout
, set_memory_ro
);
2108 frob_rodata(&mod
->init_layout
, set_memory_ro
);
2111 frob_ro_after_init(&mod
->core_layout
, set_memory_ro
);
2114 static void module_enable_nx(const struct module
*mod
)
2116 frob_rodata(&mod
->core_layout
, set_memory_nx
);
2117 frob_ro_after_init(&mod
->core_layout
, set_memory_nx
);
2118 frob_writable_data(&mod
->core_layout
, set_memory_nx
);
2119 frob_rodata(&mod
->init_layout
, set_memory_nx
);
2120 frob_writable_data(&mod
->init_layout
, set_memory_nx
);
2123 static int module_enforce_rwx_sections(Elf_Ehdr
*hdr
, Elf_Shdr
*sechdrs
,
2124 char *secstrings
, struct module
*mod
)
2126 const unsigned long shf_wx
= SHF_WRITE
|SHF_EXECINSTR
;
2129 for (i
= 0; i
< hdr
->e_shnum
; i
++) {
2130 if ((sechdrs
[i
].sh_flags
& shf_wx
) == shf_wx
) {
2131 pr_err("%s: section %s (index %d) has invalid WRITE|EXEC flags\n",
2132 mod
->name
, secstrings
+ sechdrs
[i
].sh_name
, i
);
2140 #else /* !CONFIG_STRICT_MODULE_RWX */
2141 static void module_enable_nx(const struct module
*mod
) { }
2142 static void module_enable_ro(const struct module
*mod
, bool after_init
) {}
2143 static int module_enforce_rwx_sections(Elf_Ehdr
*hdr
, Elf_Shdr
*sechdrs
,
2144 char *secstrings
, struct module
*mod
)
2148 #endif /* CONFIG_STRICT_MODULE_RWX */
2150 #ifdef CONFIG_LIVEPATCH
2152 * Persist Elf information about a module. Copy the Elf header,
2153 * section header table, section string table, and symtab section
2154 * index from info to mod->klp_info.
2156 static int copy_module_elf(struct module
*mod
, struct load_info
*info
)
2158 unsigned int size
, symndx
;
2161 size
= sizeof(*mod
->klp_info
);
2162 mod
->klp_info
= kmalloc(size
, GFP_KERNEL
);
2163 if (mod
->klp_info
== NULL
)
2167 size
= sizeof(mod
->klp_info
->hdr
);
2168 memcpy(&mod
->klp_info
->hdr
, info
->hdr
, size
);
2170 /* Elf section header table */
2171 size
= sizeof(*info
->sechdrs
) * info
->hdr
->e_shnum
;
2172 mod
->klp_info
->sechdrs
= kmemdup(info
->sechdrs
, size
, GFP_KERNEL
);
2173 if (mod
->klp_info
->sechdrs
== NULL
) {
2178 /* Elf section name string table */
2179 size
= info
->sechdrs
[info
->hdr
->e_shstrndx
].sh_size
;
2180 mod
->klp_info
->secstrings
= kmemdup(info
->secstrings
, size
, GFP_KERNEL
);
2181 if (mod
->klp_info
->secstrings
== NULL
) {
2186 /* Elf symbol section index */
2187 symndx
= info
->index
.sym
;
2188 mod
->klp_info
->symndx
= symndx
;
2191 * For livepatch modules, core_kallsyms.symtab is a complete
2192 * copy of the original symbol table. Adjust sh_addr to point
2193 * to core_kallsyms.symtab since the copy of the symtab in module
2194 * init memory is freed at the end of do_init_module().
2196 mod
->klp_info
->sechdrs
[symndx
].sh_addr
= \
2197 (unsigned long) mod
->core_kallsyms
.symtab
;
2202 kfree(mod
->klp_info
->sechdrs
);
2204 kfree(mod
->klp_info
);
2208 static void free_module_elf(struct module
*mod
)
2210 kfree(mod
->klp_info
->sechdrs
);
2211 kfree(mod
->klp_info
->secstrings
);
2212 kfree(mod
->klp_info
);
2214 #else /* !CONFIG_LIVEPATCH */
2215 static int copy_module_elf(struct module
*mod
, struct load_info
*info
)
2220 static void free_module_elf(struct module
*mod
)
2223 #endif /* CONFIG_LIVEPATCH */
2225 void __weak
module_memfree(void *module_region
)
2228 * This memory may be RO, and freeing RO memory in an interrupt is not
2229 * supported by vmalloc.
2231 WARN_ON(in_interrupt());
2232 vfree(module_region
);
2235 void __weak
module_arch_cleanup(struct module
*mod
)
2239 void __weak
module_arch_freeing_init(struct module
*mod
)
2243 /* Free a module, remove from lists, etc. */
2244 static void free_module(struct module
*mod
)
2246 trace_module_free(mod
);
2248 mod_sysfs_teardown(mod
);
2251 * We leave it in list to prevent duplicate loads, but make sure
2252 * that noone uses it while it's being deconstructed.
2254 mutex_lock(&module_mutex
);
2255 mod
->state
= MODULE_STATE_UNFORMED
;
2256 mutex_unlock(&module_mutex
);
2258 /* Remove dynamic debug info */
2259 ddebug_remove_module(mod
->name
);
2261 /* Arch-specific cleanup. */
2262 module_arch_cleanup(mod
);
2264 /* Module unload stuff */
2265 module_unload_free(mod
);
2267 /* Free any allocated parameters. */
2268 destroy_params(mod
->kp
, mod
->num_kp
);
2270 if (is_livepatch_module(mod
))
2271 free_module_elf(mod
);
2273 /* Now we can delete it from the lists */
2274 mutex_lock(&module_mutex
);
2275 /* Unlink carefully: kallsyms could be walking list. */
2276 list_del_rcu(&mod
->list
);
2277 mod_tree_remove(mod
);
2278 /* Remove this module from bug list, this uses list_del_rcu */
2279 module_bug_cleanup(mod
);
2280 /* Wait for RCU-sched synchronizing before releasing mod->list and buglist. */
2282 mutex_unlock(&module_mutex
);
2284 /* This may be empty, but that's OK */
2285 module_arch_freeing_init(mod
);
2286 module_memfree(mod
->init_layout
.base
);
2288 percpu_modfree(mod
);
2290 /* Free lock-classes; relies on the preceding sync_rcu(). */
2291 lockdep_free_key_range(mod
->core_layout
.base
, mod
->core_layout
.size
);
2293 /* Finally, free the core (containing the module structure) */
2294 module_memfree(mod
->core_layout
.base
);
2297 void *__symbol_get(const char *symbol
)
2299 struct module
*owner
;
2300 const struct kernel_symbol
*sym
;
2303 sym
= find_symbol(symbol
, &owner
, NULL
, NULL
, true, true);
2304 if (sym
&& strong_try_module_get(owner
))
2308 return sym
? (void *)kernel_symbol_value(sym
) : NULL
;
2310 EXPORT_SYMBOL_GPL(__symbol_get
);
2313 * Ensure that an exported symbol [global namespace] does not already exist
2314 * in the kernel or in some other module's exported symbol table.
2316 * You must hold the module_mutex.
2318 static int verify_exported_symbols(struct module
*mod
)
2321 struct module
*owner
;
2322 const struct kernel_symbol
*s
;
2324 const struct kernel_symbol
*sym
;
2327 { mod
->syms
, mod
->num_syms
},
2328 { mod
->gpl_syms
, mod
->num_gpl_syms
},
2329 { mod
->gpl_future_syms
, mod
->num_gpl_future_syms
},
2330 #ifdef CONFIG_UNUSED_SYMBOLS
2331 { mod
->unused_syms
, mod
->num_unused_syms
},
2332 { mod
->unused_gpl_syms
, mod
->num_unused_gpl_syms
},
2336 for (i
= 0; i
< ARRAY_SIZE(arr
); i
++) {
2337 for (s
= arr
[i
].sym
; s
< arr
[i
].sym
+ arr
[i
].num
; s
++) {
2338 if (find_symbol(kernel_symbol_name(s
), &owner
, NULL
,
2339 NULL
, true, false)) {
2340 pr_err("%s: exports duplicate symbol %s"
2342 mod
->name
, kernel_symbol_name(s
),
2343 module_name(owner
));
2351 static bool ignore_undef_symbol(Elf_Half emachine
, const char *name
)
2354 * On x86, PIC code and Clang non-PIC code may have call foo@PLT. GNU as
2355 * before 2.37 produces an unreferenced _GLOBAL_OFFSET_TABLE_ on x86-64.
2356 * i386 has a similar problem but may not deserve a fix.
2358 * If we ever have to ignore many symbols, consider refactoring the code to
2359 * only warn if referenced by a relocation.
2361 if (emachine
== EM_386
|| emachine
== EM_X86_64
)
2362 return !strcmp(name
, "_GLOBAL_OFFSET_TABLE_");
2366 /* Change all symbols so that st_value encodes the pointer directly. */
2367 static int simplify_symbols(struct module
*mod
, const struct load_info
*info
)
2369 Elf_Shdr
*symsec
= &info
->sechdrs
[info
->index
.sym
];
2370 Elf_Sym
*sym
= (void *)symsec
->sh_addr
;
2371 unsigned long secbase
;
2374 const struct kernel_symbol
*ksym
;
2376 for (i
= 1; i
< symsec
->sh_size
/ sizeof(Elf_Sym
); i
++) {
2377 const char *name
= info
->strtab
+ sym
[i
].st_name
;
2379 switch (sym
[i
].st_shndx
) {
2381 /* Ignore common symbols */
2382 if (!strncmp(name
, "__gnu_lto", 9))
2386 * We compiled with -fno-common. These are not
2387 * supposed to happen.
2389 pr_debug("Common symbol: %s\n", name
);
2390 pr_warn("%s: please compile with -fno-common\n",
2396 /* Don't need to do anything */
2397 pr_debug("Absolute symbol: 0x%08lx\n",
2398 (long)sym
[i
].st_value
);
2402 /* Livepatch symbols are resolved by livepatch */
2406 ksym
= resolve_symbol_wait(mod
, info
, name
);
2407 /* Ok if resolved. */
2408 if (ksym
&& !IS_ERR(ksym
)) {
2409 sym
[i
].st_value
= kernel_symbol_value(ksym
);
2413 /* Ok if weak or ignored. */
2415 (ELF_ST_BIND(sym
[i
].st_info
) == STB_WEAK
||
2416 ignore_undef_symbol(info
->hdr
->e_machine
, name
)))
2419 ret
= PTR_ERR(ksym
) ?: -ENOENT
;
2420 pr_warn("%s: Unknown symbol %s (err %d)\n",
2421 mod
->name
, name
, ret
);
2425 /* Divert to percpu allocation if a percpu var. */
2426 if (sym
[i
].st_shndx
== info
->index
.pcpu
)
2427 secbase
= (unsigned long)mod_percpu(mod
);
2429 secbase
= info
->sechdrs
[sym
[i
].st_shndx
].sh_addr
;
2430 sym
[i
].st_value
+= secbase
;
2438 static int apply_relocations(struct module
*mod
, const struct load_info
*info
)
2443 /* Now do relocations. */
2444 for (i
= 1; i
< info
->hdr
->e_shnum
; i
++) {
2445 unsigned int infosec
= info
->sechdrs
[i
].sh_info
;
2447 /* Not a valid relocation section? */
2448 if (infosec
>= info
->hdr
->e_shnum
)
2451 /* Don't bother with non-allocated sections */
2452 if (!(info
->sechdrs
[infosec
].sh_flags
& SHF_ALLOC
))
2455 if (info
->sechdrs
[i
].sh_flags
& SHF_RELA_LIVEPATCH
)
2456 err
= klp_apply_section_relocs(mod
, info
->sechdrs
,
2461 else if (info
->sechdrs
[i
].sh_type
== SHT_REL
)
2462 err
= apply_relocate(info
->sechdrs
, info
->strtab
,
2463 info
->index
.sym
, i
, mod
);
2464 else if (info
->sechdrs
[i
].sh_type
== SHT_RELA
)
2465 err
= apply_relocate_add(info
->sechdrs
, info
->strtab
,
2466 info
->index
.sym
, i
, mod
);
2473 /* Additional bytes needed by arch in front of individual sections */
2474 unsigned int __weak
arch_mod_section_prepend(struct module
*mod
,
2475 unsigned int section
)
2477 /* default implementation just returns zero */
2481 /* Update size with this section: return offset. */
2482 static long get_offset(struct module
*mod
, unsigned int *size
,
2483 Elf_Shdr
*sechdr
, unsigned int section
)
2487 *size
+= arch_mod_section_prepend(mod
, section
);
2488 ret
= ALIGN(*size
, sechdr
->sh_addralign
?: 1);
2489 *size
= ret
+ sechdr
->sh_size
;
2494 * Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
2495 * might -- code, read-only data, read-write data, small data. Tally
2496 * sizes, and place the offsets into sh_entsize fields: high bit means it
2499 static void layout_sections(struct module
*mod
, struct load_info
*info
)
2501 static unsigned long const masks
[][2] = {
2503 * NOTE: all executable code must be the first section
2504 * in this array; otherwise modify the text_size
2505 * finder in the two loops below
2507 { SHF_EXECINSTR
| SHF_ALLOC
, ARCH_SHF_SMALL
},
2508 { SHF_ALLOC
, SHF_WRITE
| ARCH_SHF_SMALL
},
2509 { SHF_RO_AFTER_INIT
| SHF_ALLOC
, ARCH_SHF_SMALL
},
2510 { SHF_WRITE
| SHF_ALLOC
, ARCH_SHF_SMALL
},
2511 { ARCH_SHF_SMALL
| SHF_ALLOC
, 0 }
2515 for (i
= 0; i
< info
->hdr
->e_shnum
; i
++)
2516 info
->sechdrs
[i
].sh_entsize
= ~0UL;
2518 pr_debug("Core section allocation order:\n");
2519 for (m
= 0; m
< ARRAY_SIZE(masks
); ++m
) {
2520 for (i
= 0; i
< info
->hdr
->e_shnum
; ++i
) {
2521 Elf_Shdr
*s
= &info
->sechdrs
[i
];
2522 const char *sname
= info
->secstrings
+ s
->sh_name
;
2524 if ((s
->sh_flags
& masks
[m
][0]) != masks
[m
][0]
2525 || (s
->sh_flags
& masks
[m
][1])
2526 || s
->sh_entsize
!= ~0UL
2527 || module_init_section(sname
))
2529 s
->sh_entsize
= get_offset(mod
, &mod
->core_layout
.size
, s
, i
);
2530 pr_debug("\t%s\n", sname
);
2533 case 0: /* executable */
2534 mod
->core_layout
.size
= debug_align(mod
->core_layout
.size
);
2535 mod
->core_layout
.text_size
= mod
->core_layout
.size
;
2537 case 1: /* RO: text and ro-data */
2538 mod
->core_layout
.size
= debug_align(mod
->core_layout
.size
);
2539 mod
->core_layout
.ro_size
= mod
->core_layout
.size
;
2541 case 2: /* RO after init */
2542 mod
->core_layout
.size
= debug_align(mod
->core_layout
.size
);
2543 mod
->core_layout
.ro_after_init_size
= mod
->core_layout
.size
;
2545 case 4: /* whole core */
2546 mod
->core_layout
.size
= debug_align(mod
->core_layout
.size
);
2551 pr_debug("Init section allocation order:\n");
2552 for (m
= 0; m
< ARRAY_SIZE(masks
); ++m
) {
2553 for (i
= 0; i
< info
->hdr
->e_shnum
; ++i
) {
2554 Elf_Shdr
*s
= &info
->sechdrs
[i
];
2555 const char *sname
= info
->secstrings
+ s
->sh_name
;
2557 if ((s
->sh_flags
& masks
[m
][0]) != masks
[m
][0]
2558 || (s
->sh_flags
& masks
[m
][1])
2559 || s
->sh_entsize
!= ~0UL
2560 || !module_init_section(sname
))
2562 s
->sh_entsize
= (get_offset(mod
, &mod
->init_layout
.size
, s
, i
)
2563 | INIT_OFFSET_MASK
);
2564 pr_debug("\t%s\n", sname
);
2567 case 0: /* executable */
2568 mod
->init_layout
.size
= debug_align(mod
->init_layout
.size
);
2569 mod
->init_layout
.text_size
= mod
->init_layout
.size
;
2571 case 1: /* RO: text and ro-data */
2572 mod
->init_layout
.size
= debug_align(mod
->init_layout
.size
);
2573 mod
->init_layout
.ro_size
= mod
->init_layout
.size
;
2577 * RO after init doesn't apply to init_layout (only
2578 * core_layout), so it just takes the value of ro_size.
2580 mod
->init_layout
.ro_after_init_size
= mod
->init_layout
.ro_size
;
2582 case 4: /* whole init */
2583 mod
->init_layout
.size
= debug_align(mod
->init_layout
.size
);
2589 static void set_license(struct module
*mod
, const char *license
)
2592 license
= "unspecified";
2594 if (!license_is_gpl_compatible(license
)) {
2595 if (!test_taint(TAINT_PROPRIETARY_MODULE
))
2596 pr_warn("%s: module license '%s' taints kernel.\n",
2597 mod
->name
, license
);
2598 add_taint_module(mod
, TAINT_PROPRIETARY_MODULE
,
2599 LOCKDEP_NOW_UNRELIABLE
);
2603 /* Parse tag=value strings from .modinfo section */
2604 static char *next_string(char *string
, unsigned long *secsize
)
2606 /* Skip non-zero chars */
2609 if ((*secsize
)-- <= 1)
2613 /* Skip any zero padding. */
2614 while (!string
[0]) {
2616 if ((*secsize
)-- <= 1)
2622 static char *get_next_modinfo(const struct load_info
*info
, const char *tag
,
2626 unsigned int taglen
= strlen(tag
);
2627 Elf_Shdr
*infosec
= &info
->sechdrs
[info
->index
.info
];
2628 unsigned long size
= infosec
->sh_size
;
2631 * get_modinfo() calls made before rewrite_section_headers()
2632 * must use sh_offset, as sh_addr isn't set!
2634 char *modinfo
= (char *)info
->hdr
+ infosec
->sh_offset
;
2637 size
-= prev
- modinfo
;
2638 modinfo
= next_string(prev
, &size
);
2641 for (p
= modinfo
; p
; p
= next_string(p
, &size
)) {
2642 if (strncmp(p
, tag
, taglen
) == 0 && p
[taglen
] == '=')
2643 return p
+ taglen
+ 1;
2648 static char *get_modinfo(const struct load_info
*info
, const char *tag
)
2650 return get_next_modinfo(info
, tag
, NULL
);
2653 static void setup_modinfo(struct module
*mod
, struct load_info
*info
)
2655 struct module_attribute
*attr
;
2658 for (i
= 0; (attr
= modinfo_attrs
[i
]); i
++) {
2660 attr
->setup(mod
, get_modinfo(info
, attr
->attr
.name
));
2664 static void free_modinfo(struct module
*mod
)
2666 struct module_attribute
*attr
;
2669 for (i
= 0; (attr
= modinfo_attrs
[i
]); i
++) {
2675 #ifdef CONFIG_KALLSYMS
2677 /* Lookup exported symbol in given range of kernel_symbols */
2678 static const struct kernel_symbol
*lookup_exported_symbol(const char *name
,
2679 const struct kernel_symbol
*start
,
2680 const struct kernel_symbol
*stop
)
2682 return bsearch(name
, start
, stop
- start
,
2683 sizeof(struct kernel_symbol
), cmp_name
);
2686 static int is_exported(const char *name
, unsigned long value
,
2687 const struct module
*mod
)
2689 const struct kernel_symbol
*ks
;
2691 ks
= lookup_exported_symbol(name
, __start___ksymtab
, __stop___ksymtab
);
2693 ks
= lookup_exported_symbol(name
, mod
->syms
, mod
->syms
+ mod
->num_syms
);
2695 return ks
!= NULL
&& kernel_symbol_value(ks
) == value
;
2699 static char elf_type(const Elf_Sym
*sym
, const struct load_info
*info
)
2701 const Elf_Shdr
*sechdrs
= info
->sechdrs
;
2703 if (ELF_ST_BIND(sym
->st_info
) == STB_WEAK
) {
2704 if (ELF_ST_TYPE(sym
->st_info
) == STT_OBJECT
)
2709 if (sym
->st_shndx
== SHN_UNDEF
)
2711 if (sym
->st_shndx
== SHN_ABS
|| sym
->st_shndx
== info
->index
.pcpu
)
2713 if (sym
->st_shndx
>= SHN_LORESERVE
)
2715 if (sechdrs
[sym
->st_shndx
].sh_flags
& SHF_EXECINSTR
)
2717 if (sechdrs
[sym
->st_shndx
].sh_flags
& SHF_ALLOC
2718 && sechdrs
[sym
->st_shndx
].sh_type
!= SHT_NOBITS
) {
2719 if (!(sechdrs
[sym
->st_shndx
].sh_flags
& SHF_WRITE
))
2721 else if (sechdrs
[sym
->st_shndx
].sh_flags
& ARCH_SHF_SMALL
)
2726 if (sechdrs
[sym
->st_shndx
].sh_type
== SHT_NOBITS
) {
2727 if (sechdrs
[sym
->st_shndx
].sh_flags
& ARCH_SHF_SMALL
)
2732 if (strstarts(info
->secstrings
+ sechdrs
[sym
->st_shndx
].sh_name
,
2739 static bool is_core_symbol(const Elf_Sym
*src
, const Elf_Shdr
*sechdrs
,
2740 unsigned int shnum
, unsigned int pcpundx
)
2742 const Elf_Shdr
*sec
;
2744 if (src
->st_shndx
== SHN_UNDEF
2745 || src
->st_shndx
>= shnum
2749 #ifdef CONFIG_KALLSYMS_ALL
2750 if (src
->st_shndx
== pcpundx
)
2754 sec
= sechdrs
+ src
->st_shndx
;
2755 if (!(sec
->sh_flags
& SHF_ALLOC
)
2756 #ifndef CONFIG_KALLSYMS_ALL
2757 || !(sec
->sh_flags
& SHF_EXECINSTR
)
2759 || (sec
->sh_entsize
& INIT_OFFSET_MASK
))
2766 * We only allocate and copy the strings needed by the parts of symtab
2767 * we keep. This is simple, but has the effect of making multiple
2768 * copies of duplicates. We could be more sophisticated, see
2769 * linux-kernel thread starting with
2770 * <73defb5e4bca04a6431392cc341112b1@localhost>.
2772 static void layout_symtab(struct module
*mod
, struct load_info
*info
)
2774 Elf_Shdr
*symsect
= info
->sechdrs
+ info
->index
.sym
;
2775 Elf_Shdr
*strsect
= info
->sechdrs
+ info
->index
.str
;
2777 unsigned int i
, nsrc
, ndst
, strtab_size
= 0;
2779 /* Put symbol section at end of init part of module. */
2780 symsect
->sh_flags
|= SHF_ALLOC
;
2781 symsect
->sh_entsize
= get_offset(mod
, &mod
->init_layout
.size
, symsect
,
2782 info
->index
.sym
) | INIT_OFFSET_MASK
;
2783 pr_debug("\t%s\n", info
->secstrings
+ symsect
->sh_name
);
2785 src
= (void *)info
->hdr
+ symsect
->sh_offset
;
2786 nsrc
= symsect
->sh_size
/ sizeof(*src
);
2788 /* Compute total space required for the core symbols' strtab. */
2789 for (ndst
= i
= 0; i
< nsrc
; i
++) {
2790 if (i
== 0 || is_livepatch_module(mod
) ||
2791 is_core_symbol(src
+i
, info
->sechdrs
, info
->hdr
->e_shnum
,
2792 info
->index
.pcpu
)) {
2793 strtab_size
+= strlen(&info
->strtab
[src
[i
].st_name
])+1;
2798 /* Append room for core symbols at end of core part. */
2799 info
->symoffs
= ALIGN(mod
->core_layout
.size
, symsect
->sh_addralign
?: 1);
2800 info
->stroffs
= mod
->core_layout
.size
= info
->symoffs
+ ndst
* sizeof(Elf_Sym
);
2801 mod
->core_layout
.size
+= strtab_size
;
2802 info
->core_typeoffs
= mod
->core_layout
.size
;
2803 mod
->core_layout
.size
+= ndst
* sizeof(char);
2804 mod
->core_layout
.size
= debug_align(mod
->core_layout
.size
);
2806 /* Put string table section at end of init part of module. */
2807 strsect
->sh_flags
|= SHF_ALLOC
;
2808 strsect
->sh_entsize
= get_offset(mod
, &mod
->init_layout
.size
, strsect
,
2809 info
->index
.str
) | INIT_OFFSET_MASK
;
2810 pr_debug("\t%s\n", info
->secstrings
+ strsect
->sh_name
);
2812 /* We'll tack temporary mod_kallsyms on the end. */
2813 mod
->init_layout
.size
= ALIGN(mod
->init_layout
.size
,
2814 __alignof__(struct mod_kallsyms
));
2815 info
->mod_kallsyms_init_off
= mod
->init_layout
.size
;
2816 mod
->init_layout
.size
+= sizeof(struct mod_kallsyms
);
2817 info
->init_typeoffs
= mod
->init_layout
.size
;
2818 mod
->init_layout
.size
+= nsrc
* sizeof(char);
2819 mod
->init_layout
.size
= debug_align(mod
->init_layout
.size
);
2823 * We use the full symtab and strtab which layout_symtab arranged to
2824 * be appended to the init section. Later we switch to the cut-down
2827 static void add_kallsyms(struct module
*mod
, const struct load_info
*info
)
2829 unsigned int i
, ndst
;
2833 Elf_Shdr
*symsec
= &info
->sechdrs
[info
->index
.sym
];
2835 /* Set up to point into init section. */
2836 mod
->kallsyms
= mod
->init_layout
.base
+ info
->mod_kallsyms_init_off
;
2838 mod
->kallsyms
->symtab
= (void *)symsec
->sh_addr
;
2839 mod
->kallsyms
->num_symtab
= symsec
->sh_size
/ sizeof(Elf_Sym
);
2840 /* Make sure we get permanent strtab: don't use info->strtab. */
2841 mod
->kallsyms
->strtab
= (void *)info
->sechdrs
[info
->index
.str
].sh_addr
;
2842 mod
->kallsyms
->typetab
= mod
->init_layout
.base
+ info
->init_typeoffs
;
2845 * Now populate the cut down core kallsyms for after init
2846 * and set types up while we still have access to sections.
2848 mod
->core_kallsyms
.symtab
= dst
= mod
->core_layout
.base
+ info
->symoffs
;
2849 mod
->core_kallsyms
.strtab
= s
= mod
->core_layout
.base
+ info
->stroffs
;
2850 mod
->core_kallsyms
.typetab
= mod
->core_layout
.base
+ info
->core_typeoffs
;
2851 src
= mod
->kallsyms
->symtab
;
2852 for (ndst
= i
= 0; i
< mod
->kallsyms
->num_symtab
; i
++) {
2853 mod
->kallsyms
->typetab
[i
] = elf_type(src
+ i
, info
);
2854 if (i
== 0 || is_livepatch_module(mod
) ||
2855 is_core_symbol(src
+i
, info
->sechdrs
, info
->hdr
->e_shnum
,
2856 info
->index
.pcpu
)) {
2857 mod
->core_kallsyms
.typetab
[ndst
] =
2858 mod
->kallsyms
->typetab
[i
];
2860 dst
[ndst
++].st_name
= s
- mod
->core_kallsyms
.strtab
;
2861 s
+= strlcpy(s
, &mod
->kallsyms
->strtab
[src
[i
].st_name
],
2865 mod
->core_kallsyms
.num_symtab
= ndst
;
2868 static inline void layout_symtab(struct module
*mod
, struct load_info
*info
)
2872 static void add_kallsyms(struct module
*mod
, const struct load_info
*info
)
2875 #endif /* CONFIG_KALLSYMS */
2877 static void dynamic_debug_setup(struct module
*mod
, struct _ddebug
*debug
, unsigned int num
)
2881 ddebug_add_module(debug
, num
, mod
->name
);
2884 static void dynamic_debug_remove(struct module
*mod
, struct _ddebug
*debug
)
2887 ddebug_remove_module(mod
->name
);
2890 void * __weak
module_alloc(unsigned long size
)
2892 return __vmalloc_node_range(size
, 1, VMALLOC_START
, VMALLOC_END
,
2893 GFP_KERNEL
, PAGE_KERNEL_EXEC
, VM_FLUSH_RESET_PERMS
,
2894 NUMA_NO_NODE
, __builtin_return_address(0));
2897 bool __weak
module_init_section(const char *name
)
2899 return strstarts(name
, ".init");
2902 bool __weak
module_exit_section(const char *name
)
2904 return strstarts(name
, ".exit");
2907 #ifdef CONFIG_DEBUG_KMEMLEAK
2908 static void kmemleak_load_module(const struct module
*mod
,
2909 const struct load_info
*info
)
2913 /* only scan the sections containing data */
2914 kmemleak_scan_area(mod
, sizeof(struct module
), GFP_KERNEL
);
2916 for (i
= 1; i
< info
->hdr
->e_shnum
; i
++) {
2917 /* Scan all writable sections that's not executable */
2918 if (!(info
->sechdrs
[i
].sh_flags
& SHF_ALLOC
) ||
2919 !(info
->sechdrs
[i
].sh_flags
& SHF_WRITE
) ||
2920 (info
->sechdrs
[i
].sh_flags
& SHF_EXECINSTR
))
2923 kmemleak_scan_area((void *)info
->sechdrs
[i
].sh_addr
,
2924 info
->sechdrs
[i
].sh_size
, GFP_KERNEL
);
2928 static inline void kmemleak_load_module(const struct module
*mod
,
2929 const struct load_info
*info
)
2934 #ifdef CONFIG_MODULE_SIG
2935 static int module_sig_check(struct load_info
*info
, int flags
)
2938 const unsigned long markerlen
= sizeof(MODULE_SIG_STRING
) - 1;
2940 const void *mod
= info
->hdr
;
2943 * Require flags == 0, as a module with version information
2944 * removed is no longer the module that was signed
2947 info
->len
> markerlen
&&
2948 memcmp(mod
+ info
->len
- markerlen
, MODULE_SIG_STRING
, markerlen
) == 0) {
2949 /* We truncate the module to discard the signature */
2950 info
->len
-= markerlen
;
2951 err
= mod_verify_sig(mod
, info
);
2953 info
->sig_ok
= true;
2959 * We don't permit modules to be loaded into the trusted kernels
2960 * without a valid signature on them, but if we're not enforcing,
2961 * certain errors are non-fatal.
2965 reason
= "unsigned module";
2968 reason
= "module with unsupported crypto";
2971 reason
= "module with unavailable key";
2976 * All other errors are fatal, including lack of memory,
2977 * unparseable signatures, and signature check failures --
2978 * even if signatures aren't required.
2983 if (is_module_sig_enforced()) {
2984 pr_notice("Loading of %s is rejected\n", reason
);
2985 return -EKEYREJECTED
;
2988 return security_locked_down(LOCKDOWN_MODULE_SIGNATURE
);
2990 #else /* !CONFIG_MODULE_SIG */
2991 static int module_sig_check(struct load_info
*info
, int flags
)
2995 #endif /* !CONFIG_MODULE_SIG */
2997 static int validate_section_offset(struct load_info
*info
, Elf_Shdr
*shdr
)
2999 unsigned long secend
;
3002 * Check for both overflow and offset/size being
3005 secend
= shdr
->sh_offset
+ shdr
->sh_size
;
3006 if (secend
< shdr
->sh_offset
|| secend
> info
->len
)
3013 * Sanity checks against invalid binaries, wrong arch, weird elf version.
3015 * Also do basic validity checks against section offsets and sizes, the
3016 * section name string table, and the indices used for it (sh_name).
3018 static int elf_validity_check(struct load_info
*info
)
3021 Elf_Shdr
*shdr
, *strhdr
;
3024 if (info
->len
< sizeof(*(info
->hdr
)))
3027 if (memcmp(info
->hdr
->e_ident
, ELFMAG
, SELFMAG
) != 0
3028 || info
->hdr
->e_type
!= ET_REL
3029 || !elf_check_arch(info
->hdr
)
3030 || info
->hdr
->e_shentsize
!= sizeof(Elf_Shdr
))
3034 * e_shnum is 16 bits, and sizeof(Elf_Shdr) is
3035 * known and small. So e_shnum * sizeof(Elf_Shdr)
3036 * will not overflow unsigned long on any platform.
3038 if (info
->hdr
->e_shoff
>= info
->len
3039 || (info
->hdr
->e_shnum
* sizeof(Elf_Shdr
) >
3040 info
->len
- info
->hdr
->e_shoff
))
3043 info
->sechdrs
= (void *)info
->hdr
+ info
->hdr
->e_shoff
;
3046 * Verify if the section name table index is valid.
3048 if (info
->hdr
->e_shstrndx
== SHN_UNDEF
3049 || info
->hdr
->e_shstrndx
>= info
->hdr
->e_shnum
)
3052 strhdr
= &info
->sechdrs
[info
->hdr
->e_shstrndx
];
3053 err
= validate_section_offset(info
, strhdr
);
3058 * The section name table must be NUL-terminated, as required
3059 * by the spec. This makes strcmp and pr_* calls that access
3060 * strings in the section safe.
3062 info
->secstrings
= (void *)info
->hdr
+ strhdr
->sh_offset
;
3063 if (info
->secstrings
[strhdr
->sh_size
- 1] != '\0')
3067 * The code assumes that section 0 has a length of zero and
3068 * an addr of zero, so check for it.
3070 if (info
->sechdrs
[0].sh_type
!= SHT_NULL
3071 || info
->sechdrs
[0].sh_size
!= 0
3072 || info
->sechdrs
[0].sh_addr
!= 0)
3075 for (i
= 1; i
< info
->hdr
->e_shnum
; i
++) {
3076 shdr
= &info
->sechdrs
[i
];
3077 switch (shdr
->sh_type
) {
3082 if (shdr
->sh_link
== SHN_UNDEF
3083 || shdr
->sh_link
>= info
->hdr
->e_shnum
)
3087 err
= validate_section_offset(info
, shdr
);
3089 pr_err("Invalid ELF section in module (section %u type %u)\n",
3094 if (shdr
->sh_flags
& SHF_ALLOC
) {
3095 if (shdr
->sh_name
>= strhdr
->sh_size
) {
3096 pr_err("Invalid ELF section name in module (section %u type %u)\n",
3108 #define COPY_CHUNK_SIZE (16*PAGE_SIZE)
3110 static int copy_chunked_from_user(void *dst
, const void __user
*usrc
, unsigned long len
)
3113 unsigned long n
= min(len
, COPY_CHUNK_SIZE
);
3115 if (copy_from_user(dst
, usrc
, n
) != 0)
3125 #ifdef CONFIG_LIVEPATCH
3126 static int check_modinfo_livepatch(struct module
*mod
, struct load_info
*info
)
3128 if (get_modinfo(info
, "livepatch")) {
3130 add_taint_module(mod
, TAINT_LIVEPATCH
, LOCKDEP_STILL_OK
);
3131 pr_notice_once("%s: tainting kernel with TAINT_LIVEPATCH\n",
3137 #else /* !CONFIG_LIVEPATCH */
3138 static int check_modinfo_livepatch(struct module
*mod
, struct load_info
*info
)
3140 if (get_modinfo(info
, "livepatch")) {
3141 pr_err("%s: module is marked as livepatch module, but livepatch support is disabled",
3148 #endif /* CONFIG_LIVEPATCH */
3150 static void check_modinfo_retpoline(struct module
*mod
, struct load_info
*info
)
3152 if (retpoline_module_ok(get_modinfo(info
, "retpoline")))
3155 pr_warn("%s: loading module not compiled with retpoline compiler.\n",
3159 /* Sets info->hdr and info->len. */
3160 static int copy_module_from_user(const void __user
*umod
, unsigned long len
,
3161 struct load_info
*info
)
3166 if (info
->len
< sizeof(*(info
->hdr
)))
3169 err
= security_kernel_load_data(LOADING_MODULE
, true);
3173 /* Suck in entire file: we'll want most of it. */
3174 info
->hdr
= __vmalloc(info
->len
, GFP_KERNEL
| __GFP_NOWARN
);
3178 if (copy_chunked_from_user(info
->hdr
, umod
, info
->len
) != 0) {
3183 err
= security_kernel_post_load_data((char *)info
->hdr
, info
->len
,
3184 LOADING_MODULE
, "init_module");
3192 static void free_copy(struct load_info
*info
)
3197 static int rewrite_section_headers(struct load_info
*info
, int flags
)
3201 /* This should always be true, but let's be sure. */
3202 info
->sechdrs
[0].sh_addr
= 0;
3204 for (i
= 1; i
< info
->hdr
->e_shnum
; i
++) {
3205 Elf_Shdr
*shdr
= &info
->sechdrs
[i
];
3208 * Mark all sections sh_addr with their address in the
3211 shdr
->sh_addr
= (size_t)info
->hdr
+ shdr
->sh_offset
;
3213 #ifndef CONFIG_MODULE_UNLOAD
3214 /* Don't load .exit sections */
3215 if (module_exit_section(info
->secstrings
+shdr
->sh_name
))
3216 shdr
->sh_flags
&= ~(unsigned long)SHF_ALLOC
;
3220 /* Track but don't keep modinfo and version sections. */
3221 info
->sechdrs
[info
->index
.vers
].sh_flags
&= ~(unsigned long)SHF_ALLOC
;
3222 info
->sechdrs
[info
->index
.info
].sh_flags
&= ~(unsigned long)SHF_ALLOC
;
3228 * Set up our basic convenience variables (pointers to section headers,
3229 * search for module section index etc), and do some basic section
3232 * Set info->mod to the temporary copy of the module in info->hdr. The final one
3233 * will be allocated in move_module().
3235 static int setup_load_info(struct load_info
*info
, int flags
)
3239 /* Try to find a name early so we can log errors with a module name */
3240 info
->index
.info
= find_sec(info
, ".modinfo");
3241 if (info
->index
.info
)
3242 info
->name
= get_modinfo(info
, "name");
3244 /* Find internal symbols and strings. */
3245 for (i
= 1; i
< info
->hdr
->e_shnum
; i
++) {
3246 if (info
->sechdrs
[i
].sh_type
== SHT_SYMTAB
) {
3247 info
->index
.sym
= i
;
3248 info
->index
.str
= info
->sechdrs
[i
].sh_link
;
3249 info
->strtab
= (char *)info
->hdr
3250 + info
->sechdrs
[info
->index
.str
].sh_offset
;
3255 if (info
->index
.sym
== 0) {
3256 pr_warn("%s: module has no symbols (stripped?)\n",
3257 info
->name
?: "(missing .modinfo section or name field)");
3261 info
->index
.mod
= find_sec(info
, ".gnu.linkonce.this_module");
3262 if (!info
->index
.mod
) {
3263 pr_warn("%s: No module found in object\n",
3264 info
->name
?: "(missing .modinfo section or name field)");
3267 /* This is temporary: point mod into copy of data. */
3268 info
->mod
= (void *)info
->hdr
+ info
->sechdrs
[info
->index
.mod
].sh_offset
;
3271 * If we didn't load the .modinfo 'name' field earlier, fall back to
3272 * on-disk struct mod 'name' field.
3275 info
->name
= info
->mod
->name
;
3277 if (flags
& MODULE_INIT_IGNORE_MODVERSIONS
)
3278 info
->index
.vers
= 0; /* Pretend no __versions section! */
3280 info
->index
.vers
= find_sec(info
, "__versions");
3282 info
->index
.pcpu
= find_pcpusec(info
);
3287 static int check_modinfo(struct module
*mod
, struct load_info
*info
, int flags
)
3289 const char *modmagic
= get_modinfo(info
, "vermagic");
3292 if (flags
& MODULE_INIT_IGNORE_VERMAGIC
)
3295 /* This is allowed: modprobe --force will invalidate it. */
3297 err
= try_to_force_load(mod
, "bad vermagic");
3300 } else if (!same_magic(modmagic
, vermagic
, info
->index
.vers
)) {
3301 pr_err("%s: version magic '%s' should be '%s'\n",
3302 info
->name
, modmagic
, vermagic
);
3306 if (!get_modinfo(info
, "intree")) {
3307 if (!test_taint(TAINT_OOT_MODULE
))
3308 pr_warn("%s: loading out-of-tree module taints kernel.\n",
3310 add_taint_module(mod
, TAINT_OOT_MODULE
, LOCKDEP_STILL_OK
);
3313 check_modinfo_retpoline(mod
, info
);
3315 if (get_modinfo(info
, "staging")) {
3316 add_taint_module(mod
, TAINT_CRAP
, LOCKDEP_STILL_OK
);
3317 pr_warn("%s: module is from the staging directory, the quality "
3318 "is unknown, you have been warned.\n", mod
->name
);
3321 err
= check_modinfo_livepatch(mod
, info
);
3325 /* Set up license info based on the info section */
3326 set_license(mod
, get_modinfo(info
, "license"));
3331 static int find_module_sections(struct module
*mod
, struct load_info
*info
)
3333 mod
->kp
= section_objs(info
, "__param",
3334 sizeof(*mod
->kp
), &mod
->num_kp
);
3335 mod
->syms
= section_objs(info
, "__ksymtab",
3336 sizeof(*mod
->syms
), &mod
->num_syms
);
3337 mod
->crcs
= section_addr(info
, "__kcrctab");
3338 mod
->gpl_syms
= section_objs(info
, "__ksymtab_gpl",
3339 sizeof(*mod
->gpl_syms
),
3340 &mod
->num_gpl_syms
);
3341 mod
->gpl_crcs
= section_addr(info
, "__kcrctab_gpl");
3342 mod
->gpl_future_syms
= section_objs(info
,
3343 "__ksymtab_gpl_future",
3344 sizeof(*mod
->gpl_future_syms
),
3345 &mod
->num_gpl_future_syms
);
3346 mod
->gpl_future_crcs
= section_addr(info
, "__kcrctab_gpl_future");
3348 #ifdef CONFIG_UNUSED_SYMBOLS
3349 mod
->unused_syms
= section_objs(info
, "__ksymtab_unused",
3350 sizeof(*mod
->unused_syms
),
3351 &mod
->num_unused_syms
);
3352 mod
->unused_crcs
= section_addr(info
, "__kcrctab_unused");
3353 mod
->unused_gpl_syms
= section_objs(info
, "__ksymtab_unused_gpl",
3354 sizeof(*mod
->unused_gpl_syms
),
3355 &mod
->num_unused_gpl_syms
);
3356 mod
->unused_gpl_crcs
= section_addr(info
, "__kcrctab_unused_gpl");
3358 #ifdef CONFIG_CONSTRUCTORS
3359 mod
->ctors
= section_objs(info
, ".ctors",
3360 sizeof(*mod
->ctors
), &mod
->num_ctors
);
3362 mod
->ctors
= section_objs(info
, ".init_array",
3363 sizeof(*mod
->ctors
), &mod
->num_ctors
);
3364 else if (find_sec(info
, ".init_array")) {
3366 * This shouldn't happen with same compiler and binutils
3367 * building all parts of the module.
3369 pr_warn("%s: has both .ctors and .init_array.\n",
3375 mod
->noinstr_text_start
= section_objs(info
, ".noinstr.text", 1,
3376 &mod
->noinstr_text_size
);
3378 #ifdef CONFIG_TRACEPOINTS
3379 mod
->tracepoints_ptrs
= section_objs(info
, "__tracepoints_ptrs",
3380 sizeof(*mod
->tracepoints_ptrs
),
3381 &mod
->num_tracepoints
);
3383 #ifdef CONFIG_TREE_SRCU
3384 mod
->srcu_struct_ptrs
= section_objs(info
, "___srcu_struct_ptrs",
3385 sizeof(*mod
->srcu_struct_ptrs
),
3386 &mod
->num_srcu_structs
);
3388 #ifdef CONFIG_BPF_EVENTS
3389 mod
->bpf_raw_events
= section_objs(info
, "__bpf_raw_tp_map",
3390 sizeof(*mod
->bpf_raw_events
),
3391 &mod
->num_bpf_raw_events
);
3393 #ifdef CONFIG_DEBUG_INFO_BTF_MODULES
3394 mod
->btf_data
= any_section_objs(info
, ".BTF", 1, &mod
->btf_data_size
);
3396 #ifdef CONFIG_JUMP_LABEL
3397 mod
->jump_entries
= section_objs(info
, "__jump_table",
3398 sizeof(*mod
->jump_entries
),
3399 &mod
->num_jump_entries
);
3401 #ifdef CONFIG_EVENT_TRACING
3402 mod
->trace_events
= section_objs(info
, "_ftrace_events",
3403 sizeof(*mod
->trace_events
),
3404 &mod
->num_trace_events
);
3405 mod
->trace_evals
= section_objs(info
, "_ftrace_eval_map",
3406 sizeof(*mod
->trace_evals
),
3407 &mod
->num_trace_evals
);
3409 #ifdef CONFIG_TRACING
3410 mod
->trace_bprintk_fmt_start
= section_objs(info
, "__trace_printk_fmt",
3411 sizeof(*mod
->trace_bprintk_fmt_start
),
3412 &mod
->num_trace_bprintk_fmt
);
3414 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
3415 /* sechdrs[0].sh_size is always zero */
3416 mod
->ftrace_callsites
= section_objs(info
, FTRACE_CALLSITE_SECTION
,
3417 sizeof(*mod
->ftrace_callsites
),
3418 &mod
->num_ftrace_callsites
);
3420 #ifdef CONFIG_FUNCTION_ERROR_INJECTION
3421 mod
->ei_funcs
= section_objs(info
, "_error_injection_whitelist",
3422 sizeof(*mod
->ei_funcs
),
3423 &mod
->num_ei_funcs
);
3425 #ifdef CONFIG_KPROBES
3426 mod
->kprobes_text_start
= section_objs(info
, ".kprobes.text", 1,
3427 &mod
->kprobes_text_size
);
3428 mod
->kprobe_blacklist
= section_objs(info
, "_kprobe_blacklist",
3429 sizeof(unsigned long),
3430 &mod
->num_kprobe_blacklist
);
3432 #ifdef CONFIG_HAVE_STATIC_CALL_INLINE
3433 mod
->static_call_sites
= section_objs(info
, ".static_call_sites",
3434 sizeof(*mod
->static_call_sites
),
3435 &mod
->num_static_call_sites
);
3437 mod
->extable
= section_objs(info
, "__ex_table",
3438 sizeof(*mod
->extable
), &mod
->num_exentries
);
3440 if (section_addr(info
, "__obsparm"))
3441 pr_warn("%s: Ignoring obsolete parameters\n", mod
->name
);
3443 info
->debug
= section_objs(info
, "__dyndbg",
3444 sizeof(*info
->debug
), &info
->num_debug
);
3449 static int move_module(struct module
*mod
, struct load_info
*info
)
3454 /* Do the allocs. */
3455 ptr
= module_alloc(mod
->core_layout
.size
);
3457 * The pointer to this block is stored in the module structure
3458 * which is inside the block. Just mark it as not being a
3461 kmemleak_not_leak(ptr
);
3465 memset(ptr
, 0, mod
->core_layout
.size
);
3466 mod
->core_layout
.base
= ptr
;
3468 if (mod
->init_layout
.size
) {
3469 ptr
= module_alloc(mod
->init_layout
.size
);
3471 * The pointer to this block is stored in the module structure
3472 * which is inside the block. This block doesn't need to be
3473 * scanned as it contains data and code that will be freed
3474 * after the module is initialized.
3476 kmemleak_ignore(ptr
);
3478 module_memfree(mod
->core_layout
.base
);
3481 memset(ptr
, 0, mod
->init_layout
.size
);
3482 mod
->init_layout
.base
= ptr
;
3484 mod
->init_layout
.base
= NULL
;
3486 /* Transfer each section which specifies SHF_ALLOC */
3487 pr_debug("final section addresses:\n");
3488 for (i
= 0; i
< info
->hdr
->e_shnum
; i
++) {
3490 Elf_Shdr
*shdr
= &info
->sechdrs
[i
];
3492 if (!(shdr
->sh_flags
& SHF_ALLOC
))
3495 if (shdr
->sh_entsize
& INIT_OFFSET_MASK
)
3496 dest
= mod
->init_layout
.base
3497 + (shdr
->sh_entsize
& ~INIT_OFFSET_MASK
);
3499 dest
= mod
->core_layout
.base
+ shdr
->sh_entsize
;
3501 if (shdr
->sh_type
!= SHT_NOBITS
)
3502 memcpy(dest
, (void *)shdr
->sh_addr
, shdr
->sh_size
);
3503 /* Update sh_addr to point to copy in image. */
3504 shdr
->sh_addr
= (unsigned long)dest
;
3505 pr_debug("\t0x%lx %s\n",
3506 (long)shdr
->sh_addr
, info
->secstrings
+ shdr
->sh_name
);
3512 static int check_module_license_and_versions(struct module
*mod
)
3514 int prev_taint
= test_taint(TAINT_PROPRIETARY_MODULE
);
3517 * ndiswrapper is under GPL by itself, but loads proprietary modules.
3518 * Don't use add_taint_module(), as it would prevent ndiswrapper from
3519 * using GPL-only symbols it needs.
3521 if (strcmp(mod
->name
, "ndiswrapper") == 0)
3522 add_taint(TAINT_PROPRIETARY_MODULE
, LOCKDEP_NOW_UNRELIABLE
);
3524 /* driverloader was caught wrongly pretending to be under GPL */
3525 if (strcmp(mod
->name
, "driverloader") == 0)
3526 add_taint_module(mod
, TAINT_PROPRIETARY_MODULE
,
3527 LOCKDEP_NOW_UNRELIABLE
);
3529 /* lve claims to be GPL but upstream won't provide source */
3530 if (strcmp(mod
->name
, "lve") == 0)
3531 add_taint_module(mod
, TAINT_PROPRIETARY_MODULE
,
3532 LOCKDEP_NOW_UNRELIABLE
);
3534 if (!prev_taint
&& test_taint(TAINT_PROPRIETARY_MODULE
))
3535 pr_warn("%s: module license taints kernel.\n", mod
->name
);
3537 #ifdef CONFIG_MODVERSIONS
3538 if ((mod
->num_syms
&& !mod
->crcs
)
3539 || (mod
->num_gpl_syms
&& !mod
->gpl_crcs
)
3540 || (mod
->num_gpl_future_syms
&& !mod
->gpl_future_crcs
)
3541 #ifdef CONFIG_UNUSED_SYMBOLS
3542 || (mod
->num_unused_syms
&& !mod
->unused_crcs
)
3543 || (mod
->num_unused_gpl_syms
&& !mod
->unused_gpl_crcs
)
3546 return try_to_force_load(mod
,
3547 "no versions for exported symbols");
3553 static void flush_module_icache(const struct module
*mod
)
3556 * Flush the instruction cache, since we've played with text.
3557 * Do it before processing of module parameters, so the module
3558 * can provide parameter accessor functions of its own.
3560 if (mod
->init_layout
.base
)
3561 flush_icache_range((unsigned long)mod
->init_layout
.base
,
3562 (unsigned long)mod
->init_layout
.base
3563 + mod
->init_layout
.size
);
3564 flush_icache_range((unsigned long)mod
->core_layout
.base
,
3565 (unsigned long)mod
->core_layout
.base
+ mod
->core_layout
.size
);
3568 int __weak
module_frob_arch_sections(Elf_Ehdr
*hdr
,
3576 /* module_blacklist is a comma-separated list of module names */
3577 static char *module_blacklist
;
3578 static bool blacklisted(const char *module_name
)
3583 if (!module_blacklist
)
3586 for (p
= module_blacklist
; *p
; p
+= len
) {
3587 len
= strcspn(p
, ",");
3588 if (strlen(module_name
) == len
&& !memcmp(module_name
, p
, len
))
3595 core_param(module_blacklist
, module_blacklist
, charp
, 0400);
3597 static struct module
*layout_and_allocate(struct load_info
*info
, int flags
)
3603 err
= check_modinfo(info
->mod
, info
, flags
);
3605 return ERR_PTR(err
);
3607 /* Allow arches to frob section contents and sizes. */
3608 err
= module_frob_arch_sections(info
->hdr
, info
->sechdrs
,
3609 info
->secstrings
, info
->mod
);
3611 return ERR_PTR(err
);
3613 err
= module_enforce_rwx_sections(info
->hdr
, info
->sechdrs
,
3614 info
->secstrings
, info
->mod
);
3616 return ERR_PTR(err
);
3618 /* We will do a special allocation for per-cpu sections later. */
3619 info
->sechdrs
[info
->index
.pcpu
].sh_flags
&= ~(unsigned long)SHF_ALLOC
;
3622 * Mark ro_after_init section with SHF_RO_AFTER_INIT so that
3623 * layout_sections() can put it in the right place.
3624 * Note: ro_after_init sections also have SHF_{WRITE,ALLOC} set.
3626 ndx
= find_sec(info
, ".data..ro_after_init");
3628 info
->sechdrs
[ndx
].sh_flags
|= SHF_RO_AFTER_INIT
;
3630 * Mark the __jump_table section as ro_after_init as well: these data
3631 * structures are never modified, with the exception of entries that
3632 * refer to code in the __init section, which are annotated as such
3633 * at module load time.
3635 ndx
= find_sec(info
, "__jump_table");
3637 info
->sechdrs
[ndx
].sh_flags
|= SHF_RO_AFTER_INIT
;
3640 * Determine total sizes, and put offsets in sh_entsize. For now
3641 * this is done generically; there doesn't appear to be any
3642 * special cases for the architectures.
3644 layout_sections(info
->mod
, info
);
3645 layout_symtab(info
->mod
, info
);
3647 /* Allocate and move to the final place */
3648 err
= move_module(info
->mod
, info
);
3650 return ERR_PTR(err
);
3652 /* Module has been copied to its final place now: return it. */
3653 mod
= (void *)info
->sechdrs
[info
->index
.mod
].sh_addr
;
3654 kmemleak_load_module(mod
, info
);
3658 /* mod is no longer valid after this! */
3659 static void module_deallocate(struct module
*mod
, struct load_info
*info
)
3661 percpu_modfree(mod
);
3662 module_arch_freeing_init(mod
);
3663 module_memfree(mod
->init_layout
.base
);
3664 module_memfree(mod
->core_layout
.base
);
3667 int __weak
module_finalize(const Elf_Ehdr
*hdr
,
3668 const Elf_Shdr
*sechdrs
,
3674 static int post_relocation(struct module
*mod
, const struct load_info
*info
)
3676 /* Sort exception table now relocations are done. */
3677 sort_extable(mod
->extable
, mod
->extable
+ mod
->num_exentries
);
3679 /* Copy relocated percpu area over. */
3680 percpu_modcopy(mod
, (void *)info
->sechdrs
[info
->index
.pcpu
].sh_addr
,
3681 info
->sechdrs
[info
->index
.pcpu
].sh_size
);
3683 /* Setup kallsyms-specific fields. */
3684 add_kallsyms(mod
, info
);
3686 /* Arch-specific module finalizing. */
3687 return module_finalize(info
->hdr
, info
->sechdrs
, mod
);
3690 /* Is this module of this name done loading? No locks held. */
3691 static bool finished_loading(const char *name
)
3697 * The module_mutex should not be a heavily contended lock;
3698 * if we get the occasional sleep here, we'll go an extra iteration
3699 * in the wait_event_interruptible(), which is harmless.
3701 sched_annotate_sleep();
3702 mutex_lock(&module_mutex
);
3703 mod
= find_module_all(name
, strlen(name
), true);
3704 ret
= !mod
|| mod
->state
== MODULE_STATE_LIVE
;
3705 mutex_unlock(&module_mutex
);
3710 /* Call module constructors. */
3711 static void do_mod_ctors(struct module
*mod
)
3713 #ifdef CONFIG_CONSTRUCTORS
3716 for (i
= 0; i
< mod
->num_ctors
; i
++)
3721 /* For freeing module_init on success, in case kallsyms traversing */
3722 struct mod_initfree
{
3723 struct llist_node node
;
3727 static void do_free_init(struct work_struct
*w
)
3729 struct llist_node
*pos
, *n
, *list
;
3730 struct mod_initfree
*initfree
;
3732 list
= llist_del_all(&init_free_list
);
3736 llist_for_each_safe(pos
, n
, list
) {
3737 initfree
= container_of(pos
, struct mod_initfree
, node
);
3738 module_memfree(initfree
->module_init
);
3744 * This is where the real work happens.
3746 * Keep it uninlined to provide a reliable breakpoint target, e.g. for the gdb
3747 * helper command 'lx-symbols'.
3749 static noinline
int do_init_module(struct module
*mod
)
3752 struct mod_initfree
*freeinit
;
3754 freeinit
= kmalloc(sizeof(*freeinit
), GFP_KERNEL
);
3759 freeinit
->module_init
= mod
->init_layout
.base
;
3762 * We want to find out whether @mod uses async during init. Clear
3763 * PF_USED_ASYNC. async_schedule*() will set it.
3765 current
->flags
&= ~PF_USED_ASYNC
;
3768 /* Start the module */
3769 if (mod
->init
!= NULL
)
3770 ret
= do_one_initcall(mod
->init
);
3772 goto fail_free_freeinit
;
3775 pr_warn("%s: '%s'->init suspiciously returned %d, it should "
3776 "follow 0/-E convention\n"
3777 "%s: loading module anyway...\n",
3778 __func__
, mod
->name
, ret
, __func__
);
3782 /* Now it's a first class citizen! */
3783 mod
->state
= MODULE_STATE_LIVE
;
3784 blocking_notifier_call_chain(&module_notify_list
,
3785 MODULE_STATE_LIVE
, mod
);
3787 /* Delay uevent until module has finished its init routine */
3788 kobject_uevent(&mod
->mkobj
.kobj
, KOBJ_ADD
);
3791 * We need to finish all async code before the module init sequence
3792 * is done. This has potential to deadlock. For example, a newly
3793 * detected block device can trigger request_module() of the
3794 * default iosched from async probing task. Once userland helper
3795 * reaches here, async_synchronize_full() will wait on the async
3796 * task waiting on request_module() and deadlock.
3798 * This deadlock is avoided by perfomring async_synchronize_full()
3799 * iff module init queued any async jobs. This isn't a full
3800 * solution as it will deadlock the same if module loading from
3801 * async jobs nests more than once; however, due to the various
3802 * constraints, this hack seems to be the best option for now.
3803 * Please refer to the following thread for details.
3805 * http://thread.gmane.org/gmane.linux.kernel/1420814
3807 if (!mod
->async_probe_requested
&& (current
->flags
& PF_USED_ASYNC
))
3808 async_synchronize_full();
3810 ftrace_free_mem(mod
, mod
->init_layout
.base
, mod
->init_layout
.base
+
3811 mod
->init_layout
.size
);
3812 mutex_lock(&module_mutex
);
3813 /* Drop initial reference. */
3815 trim_init_extable(mod
);
3816 #ifdef CONFIG_KALLSYMS
3817 /* Switch to core kallsyms now init is done: kallsyms may be walking! */
3818 rcu_assign_pointer(mod
->kallsyms
, &mod
->core_kallsyms
);
3820 module_enable_ro(mod
, true);
3821 mod_tree_remove_init(mod
);
3822 module_arch_freeing_init(mod
);
3823 mod
->init_layout
.base
= NULL
;
3824 mod
->init_layout
.size
= 0;
3825 mod
->init_layout
.ro_size
= 0;
3826 mod
->init_layout
.ro_after_init_size
= 0;
3827 mod
->init_layout
.text_size
= 0;
3828 #ifdef CONFIG_DEBUG_INFO_BTF_MODULES
3829 /* .BTF is not SHF_ALLOC and will get removed, so sanitize pointer */
3830 mod
->btf_data
= NULL
;
3833 * We want to free module_init, but be aware that kallsyms may be
3834 * walking this with preempt disabled. In all the failure paths, we
3835 * call synchronize_rcu(), but we don't want to slow down the success
3836 * path. module_memfree() cannot be called in an interrupt, so do the
3837 * work and call synchronize_rcu() in a work queue.
3839 * Note that module_alloc() on most architectures creates W+X page
3840 * mappings which won't be cleaned up until do_free_init() runs. Any
3841 * code such as mark_rodata_ro() which depends on those mappings to
3842 * be cleaned up needs to sync with the queued work - ie
3845 if (llist_add(&freeinit
->node
, &init_free_list
))
3846 schedule_work(&init_free_wq
);
3848 mutex_unlock(&module_mutex
);
3849 wake_up_all(&module_wq
);
3856 /* Try to protect us from buggy refcounters. */
3857 mod
->state
= MODULE_STATE_GOING
;
3860 blocking_notifier_call_chain(&module_notify_list
,
3861 MODULE_STATE_GOING
, mod
);
3862 klp_module_going(mod
);
3863 ftrace_release_mod(mod
);
3865 wake_up_all(&module_wq
);
3869 static int may_init_module(void)
3871 if (!capable(CAP_SYS_MODULE
) || modules_disabled
)
3878 * We try to place it in the list now to make sure it's unique before
3879 * we dedicate too many resources. In particular, temporary percpu
3880 * memory exhaustion.
3882 static int add_unformed_module(struct module
*mod
)
3887 mod
->state
= MODULE_STATE_UNFORMED
;
3890 mutex_lock(&module_mutex
);
3891 old
= find_module_all(mod
->name
, strlen(mod
->name
), true);
3893 if (old
->state
!= MODULE_STATE_LIVE
) {
3894 /* Wait in case it fails to load. */
3895 mutex_unlock(&module_mutex
);
3896 err
= wait_event_interruptible(module_wq
,
3897 finished_loading(mod
->name
));
3905 mod_update_bounds(mod
);
3906 list_add_rcu(&mod
->list
, &modules
);
3907 mod_tree_insert(mod
);
3911 mutex_unlock(&module_mutex
);
3916 static int complete_formation(struct module
*mod
, struct load_info
*info
)
3920 mutex_lock(&module_mutex
);
3922 /* Find duplicate symbols (must be called under lock). */
3923 err
= verify_exported_symbols(mod
);
3927 /* This relies on module_mutex for list integrity. */
3928 module_bug_finalize(info
->hdr
, info
->sechdrs
, mod
);
3930 module_enable_ro(mod
, false);
3931 module_enable_nx(mod
);
3932 module_enable_x(mod
);
3935 * Mark state as coming so strong_try_module_get() ignores us,
3936 * but kallsyms etc. can see us.
3938 mod
->state
= MODULE_STATE_COMING
;
3939 mutex_unlock(&module_mutex
);
3944 mutex_unlock(&module_mutex
);
3948 static int prepare_coming_module(struct module
*mod
)
3952 ftrace_module_enable(mod
);
3953 err
= klp_module_coming(mod
);
3957 err
= blocking_notifier_call_chain_robust(&module_notify_list
,
3958 MODULE_STATE_COMING
, MODULE_STATE_GOING
, mod
);
3959 err
= notifier_to_errno(err
);
3961 klp_module_going(mod
);
3966 static int unknown_module_param_cb(char *param
, char *val
, const char *modname
,
3969 struct module
*mod
= arg
;
3972 if (strcmp(param
, "async_probe") == 0) {
3973 mod
->async_probe_requested
= true;
3977 /* Check for magic 'dyndbg' arg */
3978 ret
= ddebug_dyndbg_module_param_cb(param
, val
, modname
);
3980 pr_warn("%s: unknown parameter '%s' ignored\n", modname
, param
);
3985 * Allocate and load the module: note that size of section 0 is always
3986 * zero, and we rely on this for optional sections.
3988 static int load_module(struct load_info
*info
, const char __user
*uargs
,
3996 * Do the signature check (if any) first. All that
3997 * the signature check needs is info->len, it does
3998 * not need any of the section info. That can be
3999 * set up later. This will minimize the chances
4000 * of a corrupt module causing problems before
4001 * we even get to the signature check.
4003 * The check will also adjust info->len by stripping
4004 * off the sig length at the end of the module, making
4005 * checks against info->len more correct.
4007 err
= module_sig_check(info
, flags
);
4012 * Do basic sanity checks against the ELF header and
4015 err
= elf_validity_check(info
);
4017 pr_err("Module has invalid ELF structures\n");
4022 * Everything checks out, so set up the section info
4023 * in the info structure.
4025 err
= setup_load_info(info
, flags
);
4030 * Now that we know we have the correct module name, check
4031 * if it's blacklisted.
4033 if (blacklisted(info
->name
)) {
4035 pr_err("Module %s is blacklisted\n", info
->name
);
4039 err
= rewrite_section_headers(info
, flags
);
4043 /* Check module struct version now, before we try to use module. */
4044 if (!check_modstruct_version(info
, info
->mod
)) {
4049 /* Figure out module layout, and allocate all the memory. */
4050 mod
= layout_and_allocate(info
, flags
);
4056 audit_log_kern_module(mod
->name
);
4058 /* Reserve our place in the list. */
4059 err
= add_unformed_module(mod
);
4063 #ifdef CONFIG_MODULE_SIG
4064 mod
->sig_ok
= info
->sig_ok
;
4066 pr_notice_once("%s: module verification failed: signature "
4067 "and/or required key missing - tainting "
4068 "kernel\n", mod
->name
);
4069 add_taint_module(mod
, TAINT_UNSIGNED_MODULE
, LOCKDEP_STILL_OK
);
4073 /* To avoid stressing percpu allocator, do this once we're unique. */
4074 err
= percpu_modalloc(mod
, info
);
4078 /* Now module is in final location, initialize linked lists, etc. */
4079 err
= module_unload_init(mod
);
4083 init_param_lock(mod
);
4086 * Now we've got everything in the final locations, we can
4087 * find optional sections.
4089 err
= find_module_sections(mod
, info
);
4093 err
= check_module_license_and_versions(mod
);
4097 /* Set up MODINFO_ATTR fields */
4098 setup_modinfo(mod
, info
);
4100 /* Fix up syms, so that st_value is a pointer to location. */
4101 err
= simplify_symbols(mod
, info
);
4105 err
= apply_relocations(mod
, info
);
4109 err
= post_relocation(mod
, info
);
4113 flush_module_icache(mod
);
4115 /* Now copy in args */
4116 mod
->args
= strndup_user(uargs
, ~0UL >> 1);
4117 if (IS_ERR(mod
->args
)) {
4118 err
= PTR_ERR(mod
->args
);
4119 goto free_arch_cleanup
;
4122 dynamic_debug_setup(mod
, info
->debug
, info
->num_debug
);
4124 /* Ftrace init must be called in the MODULE_STATE_UNFORMED state */
4125 ftrace_module_init(mod
);
4127 /* Finally it's fully formed, ready to start executing. */
4128 err
= complete_formation(mod
, info
);
4130 goto ddebug_cleanup
;
4132 err
= prepare_coming_module(mod
);
4136 /* Module is ready to execute: parsing args may do that. */
4137 after_dashes
= parse_args(mod
->name
, mod
->args
, mod
->kp
, mod
->num_kp
,
4139 unknown_module_param_cb
);
4140 if (IS_ERR(after_dashes
)) {
4141 err
= PTR_ERR(after_dashes
);
4142 goto coming_cleanup
;
4143 } else if (after_dashes
) {
4144 pr_warn("%s: parameters '%s' after `--' ignored\n",
4145 mod
->name
, after_dashes
);
4148 /* Link in to sysfs. */
4149 err
= mod_sysfs_setup(mod
, info
, mod
->kp
, mod
->num_kp
);
4151 goto coming_cleanup
;
4153 if (is_livepatch_module(mod
)) {
4154 err
= copy_module_elf(mod
, info
);
4159 /* Get rid of temporary copy. */
4163 trace_module_load(mod
);
4165 return do_init_module(mod
);
4168 mod_sysfs_teardown(mod
);
4170 mod
->state
= MODULE_STATE_GOING
;
4171 destroy_params(mod
->kp
, mod
->num_kp
);
4172 blocking_notifier_call_chain(&module_notify_list
,
4173 MODULE_STATE_GOING
, mod
);
4174 klp_module_going(mod
);
4176 mod
->state
= MODULE_STATE_GOING
;
4177 /* module_bug_cleanup needs module_mutex protection */
4178 mutex_lock(&module_mutex
);
4179 module_bug_cleanup(mod
);
4180 mutex_unlock(&module_mutex
);
4183 ftrace_release_mod(mod
);
4184 dynamic_debug_remove(mod
, info
->debug
);
4188 module_arch_cleanup(mod
);
4192 module_unload_free(mod
);
4194 mutex_lock(&module_mutex
);
4195 /* Unlink carefully: kallsyms could be walking list. */
4196 list_del_rcu(&mod
->list
);
4197 mod_tree_remove(mod
);
4198 wake_up_all(&module_wq
);
4199 /* Wait for RCU-sched synchronizing before releasing mod->list. */
4201 mutex_unlock(&module_mutex
);
4203 /* Free lock-classes; relies on the preceding sync_rcu() */
4204 lockdep_free_key_range(mod
->core_layout
.base
, mod
->core_layout
.size
);
4206 module_deallocate(mod
, info
);
4212 SYSCALL_DEFINE3(init_module
, void __user
*, umod
,
4213 unsigned long, len
, const char __user
*, uargs
)
4216 struct load_info info
= { };
4218 err
= may_init_module();
4222 pr_debug("init_module: umod=%p, len=%lu, uargs=%p\n",
4225 err
= copy_module_from_user(umod
, len
, &info
);
4229 return load_module(&info
, uargs
, 0);
4232 SYSCALL_DEFINE3(finit_module
, int, fd
, const char __user
*, uargs
, int, flags
)
4234 struct load_info info
= { };
4238 err
= may_init_module();
4242 pr_debug("finit_module: fd=%d, uargs=%p, flags=%i\n", fd
, uargs
, flags
);
4244 if (flags
& ~(MODULE_INIT_IGNORE_MODVERSIONS
4245 |MODULE_INIT_IGNORE_VERMAGIC
))
4248 err
= kernel_read_file_from_fd(fd
, 0, &hdr
, INT_MAX
, NULL
,
4255 return load_module(&info
, uargs
, flags
);
4258 static inline int within(unsigned long addr
, void *start
, unsigned long size
)
4260 return ((void *)addr
>= start
&& (void *)addr
< start
+ size
);
4263 #ifdef CONFIG_KALLSYMS
4265 * This ignores the intensely annoying "mapping symbols" found
4266 * in ARM ELF files: $a, $t and $d.
4268 static inline int is_arm_mapping_symbol(const char *str
)
4270 if (str
[0] == '.' && str
[1] == 'L')
4272 return str
[0] == '$' && strchr("axtd", str
[1])
4273 && (str
[2] == '\0' || str
[2] == '.');
4276 static const char *kallsyms_symbol_name(struct mod_kallsyms
*kallsyms
, unsigned int symnum
)
4278 return kallsyms
->strtab
+ kallsyms
->symtab
[symnum
].st_name
;
4282 * Given a module and address, find the corresponding symbol and return its name
4283 * while providing its size and offset if needed.
4285 static const char *find_kallsyms_symbol(struct module
*mod
,
4287 unsigned long *size
,
4288 unsigned long *offset
)
4290 unsigned int i
, best
= 0;
4291 unsigned long nextval
, bestval
;
4292 struct mod_kallsyms
*kallsyms
= rcu_dereference_sched(mod
->kallsyms
);
4294 /* At worse, next value is at end of module */
4295 if (within_module_init(addr
, mod
))
4296 nextval
= (unsigned long)mod
->init_layout
.base
+mod
->init_layout
.text_size
;
4298 nextval
= (unsigned long)mod
->core_layout
.base
+mod
->core_layout
.text_size
;
4300 bestval
= kallsyms_symbol_value(&kallsyms
->symtab
[best
]);
4303 * Scan for closest preceding symbol, and next symbol. (ELF
4304 * starts real symbols at 1).
4306 for (i
= 1; i
< kallsyms
->num_symtab
; i
++) {
4307 const Elf_Sym
*sym
= &kallsyms
->symtab
[i
];
4308 unsigned long thisval
= kallsyms_symbol_value(sym
);
4310 if (sym
->st_shndx
== SHN_UNDEF
)
4314 * We ignore unnamed symbols: they're uninformative
4315 * and inserted at a whim.
4317 if (*kallsyms_symbol_name(kallsyms
, i
) == '\0'
4318 || is_arm_mapping_symbol(kallsyms_symbol_name(kallsyms
, i
)))
4321 if (thisval
<= addr
&& thisval
> bestval
) {
4325 if (thisval
> addr
&& thisval
< nextval
)
4333 *size
= nextval
- bestval
;
4335 *offset
= addr
- bestval
;
4337 return kallsyms_symbol_name(kallsyms
, best
);
4340 void * __weak
dereference_module_function_descriptor(struct module
*mod
,
4347 * For kallsyms to ask for address resolution. NULL means not found. Careful
4348 * not to lock to avoid deadlock on oopses, simply disable preemption.
4350 const char *module_address_lookup(unsigned long addr
,
4351 unsigned long *size
,
4352 unsigned long *offset
,
4356 const char *ret
= NULL
;
4360 mod
= __module_address(addr
);
4363 *modname
= mod
->name
;
4365 ret
= find_kallsyms_symbol(mod
, addr
, size
, offset
);
4367 /* Make a copy in here where it's safe */
4369 strncpy(namebuf
, ret
, KSYM_NAME_LEN
- 1);
4377 int lookup_module_symbol_name(unsigned long addr
, char *symname
)
4382 list_for_each_entry_rcu(mod
, &modules
, list
) {
4383 if (mod
->state
== MODULE_STATE_UNFORMED
)
4385 if (within_module(addr
, mod
)) {
4388 sym
= find_kallsyms_symbol(mod
, addr
, NULL
, NULL
);
4392 strlcpy(symname
, sym
, KSYM_NAME_LEN
);
4402 int lookup_module_symbol_attrs(unsigned long addr
, unsigned long *size
,
4403 unsigned long *offset
, char *modname
, char *name
)
4408 list_for_each_entry_rcu(mod
, &modules
, list
) {
4409 if (mod
->state
== MODULE_STATE_UNFORMED
)
4411 if (within_module(addr
, mod
)) {
4414 sym
= find_kallsyms_symbol(mod
, addr
, size
, offset
);
4418 strlcpy(modname
, mod
->name
, MODULE_NAME_LEN
);
4420 strlcpy(name
, sym
, KSYM_NAME_LEN
);
4430 int module_get_kallsym(unsigned int symnum
, unsigned long *value
, char *type
,
4431 char *name
, char *module_name
, int *exported
)
4436 list_for_each_entry_rcu(mod
, &modules
, list
) {
4437 struct mod_kallsyms
*kallsyms
;
4439 if (mod
->state
== MODULE_STATE_UNFORMED
)
4441 kallsyms
= rcu_dereference_sched(mod
->kallsyms
);
4442 if (symnum
< kallsyms
->num_symtab
) {
4443 const Elf_Sym
*sym
= &kallsyms
->symtab
[symnum
];
4445 *value
= kallsyms_symbol_value(sym
);
4446 *type
= kallsyms
->typetab
[symnum
];
4447 strlcpy(name
, kallsyms_symbol_name(kallsyms
, symnum
), KSYM_NAME_LEN
);
4448 strlcpy(module_name
, mod
->name
, MODULE_NAME_LEN
);
4449 *exported
= is_exported(name
, *value
, mod
);
4453 symnum
-= kallsyms
->num_symtab
;
4459 /* Given a module and name of symbol, find and return the symbol's value */
4460 static unsigned long find_kallsyms_symbol_value(struct module
*mod
, const char *name
)
4463 struct mod_kallsyms
*kallsyms
= rcu_dereference_sched(mod
->kallsyms
);
4465 for (i
= 0; i
< kallsyms
->num_symtab
; i
++) {
4466 const Elf_Sym
*sym
= &kallsyms
->symtab
[i
];
4468 if (strcmp(name
, kallsyms_symbol_name(kallsyms
, i
)) == 0 &&
4469 sym
->st_shndx
!= SHN_UNDEF
)
4470 return kallsyms_symbol_value(sym
);
4475 /* Look for this name: can be of form module:name. */
4476 unsigned long module_kallsyms_lookup_name(const char *name
)
4480 unsigned long ret
= 0;
4482 /* Don't lock: we're in enough trouble already. */
4484 if ((colon
= strnchr(name
, MODULE_NAME_LEN
, ':')) != NULL
) {
4485 if ((mod
= find_module_all(name
, colon
- name
, false)) != NULL
)
4486 ret
= find_kallsyms_symbol_value(mod
, colon
+1);
4488 list_for_each_entry_rcu(mod
, &modules
, list
) {
4489 if (mod
->state
== MODULE_STATE_UNFORMED
)
4491 if ((ret
= find_kallsyms_symbol_value(mod
, name
)) != 0)
4499 int module_kallsyms_on_each_symbol(int (*fn
)(void *, const char *,
4500 struct module
*, unsigned long),
4507 module_assert_mutex();
4509 list_for_each_entry(mod
, &modules
, list
) {
4510 /* We hold module_mutex: no need for rcu_dereference_sched */
4511 struct mod_kallsyms
*kallsyms
= mod
->kallsyms
;
4513 if (mod
->state
== MODULE_STATE_UNFORMED
)
4515 for (i
= 0; i
< kallsyms
->num_symtab
; i
++) {
4516 const Elf_Sym
*sym
= &kallsyms
->symtab
[i
];
4518 if (sym
->st_shndx
== SHN_UNDEF
)
4521 ret
= fn(data
, kallsyms_symbol_name(kallsyms
, i
),
4522 mod
, kallsyms_symbol_value(sym
));
4529 #endif /* CONFIG_KALLSYMS */
4531 /* Maximum number of characters written by module_flags() */
4532 #define MODULE_FLAGS_BUF_SIZE (TAINT_FLAGS_COUNT + 4)
4534 /* Keep in sync with MODULE_FLAGS_BUF_SIZE !!! */
4535 static char *module_flags(struct module
*mod
, char *buf
)
4539 BUG_ON(mod
->state
== MODULE_STATE_UNFORMED
);
4541 mod
->state
== MODULE_STATE_GOING
||
4542 mod
->state
== MODULE_STATE_COMING
) {
4544 bx
+= module_flags_taint(mod
, buf
+ bx
);
4545 /* Show a - for module-is-being-unloaded */
4546 if (mod
->state
== MODULE_STATE_GOING
)
4548 /* Show a + for module-is-being-loaded */
4549 if (mod
->state
== MODULE_STATE_COMING
)
4558 #ifdef CONFIG_PROC_FS
4559 /* Called by the /proc file system to return a list of modules. */
4560 static void *m_start(struct seq_file
*m
, loff_t
*pos
)
4562 mutex_lock(&module_mutex
);
4563 return seq_list_start(&modules
, *pos
);
4566 static void *m_next(struct seq_file
*m
, void *p
, loff_t
*pos
)
4568 return seq_list_next(p
, &modules
, pos
);
4571 static void m_stop(struct seq_file
*m
, void *p
)
4573 mutex_unlock(&module_mutex
);
4576 static int m_show(struct seq_file
*m
, void *p
)
4578 struct module
*mod
= list_entry(p
, struct module
, list
);
4579 char buf
[MODULE_FLAGS_BUF_SIZE
];
4582 /* We always ignore unformed modules. */
4583 if (mod
->state
== MODULE_STATE_UNFORMED
)
4586 seq_printf(m
, "%s %u",
4587 mod
->name
, mod
->init_layout
.size
+ mod
->core_layout
.size
);
4588 print_unload_info(m
, mod
);
4590 /* Informative for users. */
4591 seq_printf(m
, " %s",
4592 mod
->state
== MODULE_STATE_GOING
? "Unloading" :
4593 mod
->state
== MODULE_STATE_COMING
? "Loading" :
4595 /* Used by oprofile and other similar tools. */
4596 value
= m
->private ? NULL
: mod
->core_layout
.base
;
4597 seq_printf(m
, " 0x%px", value
);
4601 seq_printf(m
, " %s", module_flags(mod
, buf
));
4608 * Format: modulename size refcount deps address
4610 * Where refcount is a number or -, and deps is a comma-separated list
4613 static const struct seq_operations modules_op
= {
4621 * This also sets the "private" pointer to non-NULL if the
4622 * kernel pointers should be hidden (so you can just test
4623 * "m->private" to see if you should keep the values private).
4625 * We use the same logic as for /proc/kallsyms.
4627 static int modules_open(struct inode
*inode
, struct file
*file
)
4629 int err
= seq_open(file
, &modules_op
);
4632 struct seq_file
*m
= file
->private_data
;
4633 m
->private = kallsyms_show_value(file
->f_cred
) ? NULL
: (void *)8ul;
4639 static const struct proc_ops modules_proc_ops
= {
4640 .proc_flags
= PROC_ENTRY_PERMANENT
,
4641 .proc_open
= modules_open
,
4642 .proc_read
= seq_read
,
4643 .proc_lseek
= seq_lseek
,
4644 .proc_release
= seq_release
,
4647 static int __init
proc_modules_init(void)
4649 proc_create("modules", 0, NULL
, &modules_proc_ops
);
4652 module_init(proc_modules_init
);
4655 /* Given an address, look for it in the module exception tables. */
4656 const struct exception_table_entry
*search_module_extables(unsigned long addr
)
4658 const struct exception_table_entry
*e
= NULL
;
4662 mod
= __module_address(addr
);
4666 if (!mod
->num_exentries
)
4669 e
= search_extable(mod
->extable
,
4676 * Now, if we found one, we are running inside it now, hence
4677 * we cannot unload the module, hence no refcnt needed.
4683 * is_module_address() - is this address inside a module?
4684 * @addr: the address to check.
4686 * See is_module_text_address() if you simply want to see if the address
4687 * is code (not data).
4689 bool is_module_address(unsigned long addr
)
4694 ret
= __module_address(addr
) != NULL
;
4701 * __module_address() - get the module which contains an address.
4702 * @addr: the address.
4704 * Must be called with preempt disabled or module mutex held so that
4705 * module doesn't get freed during this.
4707 struct module
*__module_address(unsigned long addr
)
4711 if (addr
< module_addr_min
|| addr
> module_addr_max
)
4714 module_assert_mutex_or_preempt();
4716 mod
= mod_find(addr
);
4718 BUG_ON(!within_module(addr
, mod
));
4719 if (mod
->state
== MODULE_STATE_UNFORMED
)
4726 * is_module_text_address() - is this address inside module code?
4727 * @addr: the address to check.
4729 * See is_module_address() if you simply want to see if the address is
4730 * anywhere in a module. See kernel_text_address() for testing if an
4731 * address corresponds to kernel or module code.
4733 bool is_module_text_address(unsigned long addr
)
4738 ret
= __module_text_address(addr
) != NULL
;
4745 * __module_text_address() - get the module whose code contains an address.
4746 * @addr: the address.
4748 * Must be called with preempt disabled or module mutex held so that
4749 * module doesn't get freed during this.
4751 struct module
*__module_text_address(unsigned long addr
)
4753 struct module
*mod
= __module_address(addr
);
4755 /* Make sure it's within the text section. */
4756 if (!within(addr
, mod
->init_layout
.base
, mod
->init_layout
.text_size
)
4757 && !within(addr
, mod
->core_layout
.base
, mod
->core_layout
.text_size
))
4763 /* Don't grab lock, we're oopsing. */
4764 void print_modules(void)
4767 char buf
[MODULE_FLAGS_BUF_SIZE
];
4769 printk(KERN_DEFAULT
"Modules linked in:");
4770 /* Most callers should already have preempt disabled, but make sure */
4772 list_for_each_entry_rcu(mod
, &modules
, list
) {
4773 if (mod
->state
== MODULE_STATE_UNFORMED
)
4775 pr_cont(" %s%s", mod
->name
, module_flags(mod
, buf
));
4778 if (last_unloaded_module
[0])
4779 pr_cont(" [last unloaded: %s]", last_unloaded_module
);
4783 #ifdef CONFIG_MODVERSIONS
4785 * Generate the signature for all relevant module structures here.
4786 * If these change, we don't want to try to parse the module.
4788 void module_layout(struct module
*mod
,
4789 struct modversion_info
*ver
,
4790 struct kernel_param
*kp
,
4791 struct kernel_symbol
*ks
,
4792 struct tracepoint
* const *tp
)
4795 EXPORT_SYMBOL(module_layout
);